Jump to content
  • entries
    56
  • comments
    517
  • views
    259,355

About this blog

Moto Mind is a technical blog written by Paul Olesen who is a powertrain engineer working in the motorcycle industry. The blog covers a wide variety of topics relating to two and four stroke engine performance, design, and optimization.

Entries in this blog

 

Workshop Basics For At Home Engine Building

I like to compare building an engine to performing open heart surgery. The precision and organization that goes into open heart surgery is exactly the mindset you need as you begin to rebuild your engine. Just like an operating room, I require my workspace to be as clean as possible. In the industry, companies have dedicated rooms just for engine building. These rooms are equipped with dust management systems, precise temperature control, and spotless work surfaces. I don’t expect the home mechanic to have this intense of a setup, but you should aim to have the cleanest work area possible. One of the first things you will need to do is make sure the area you are working in is free of dirt. Use a vacuum to suck up dirt from work surfaces and the floor. Occasionally you’ll drop a part on the floor and the last thing you want is for it to wind up covered in dirt. This should go without saying, but don’t try building an engine where metal is being ground or cut. The temperature of your build area is also important. Parts are designed, manufactured, and inspected at 68°F (20°C). This means that in order for you to correctly measure a part during your build it should be at the standard temperature of 68°F. As long as you are close to 68°F you’ll be fine, however building an engine in a cold unheated garage in the dead of winter may not yield accurate results. Conversely, measuring parts in a sweatbox of a garage without airconditioning will not work that well either. Let’s move on to other aspects of the workshop that are important. Until recently, my workbench was old and the work surface wasn't the smoothest or cleanest. It is difficult to get all the dirt out of plywood so I like to line my plywood tops with paper or cardboard then replace as often as necessary throughout the build to ensure cleanliness is kept up. This practice ensures I’m not working on a dirty surface and exposing parts to unnecessary dirt which could cause scratches or damage. If you have the luxury of working on a laminate counter top or other hard smooth surface more power to you. Just remember to wipe the surface clean as you go to keep dirt to a minimum. Lighting is one area that can be overlooked for many home mechanics. Make things easy on your eyes and be sure you have a good source of lighting where you are working. This way you’ll easily be able to see the wear in used parts, accurately read measuring equipment, and correctly assemble new parts. I prefer good overhead lighting when available, but when unavailable good portable lighting can be just as effective. Portable lights affixed to stands that can be raised above shoulder level work well. Tool storage and how you choose to handle your tools throughout the build comes down to personal preference. My tools are stored in a two level rolling toolbox. I can easily roll my toolbox from the motorcycle lift to my workbench once the engine has been removed. Instead of putting tools away after I’ve used them for a given task I like to leave them out. By keeping them neatly organized I don’t have to go digging for them later down the road. The tools I frequently use are then set either on my workbench or on a rolling cart so I can quickly grab them throughout the build. Allocating space to set parts aside as they are disassembled is important. Laying out and keeping a completely disassembled engine organized requires some room. A 3’ x 4’ area dedicated to storing disassembled engine parts will usually work. Alternatively a rolling cart with multiple levels is a handy option as it allows better organization and you can wheel parts around with ease. Make sure you are storing parts on nice smooth soft surfaces. Laying out parts on something like a grated metal shelf or work top wouldn’t be a good idea as the parts could be damaged when they contact the surface. This is especially true of gasket surfaces on covers which mar pretty easily. Another must is to never stack parts on top of one another. Make sure the area you have chosen to lay out parts is dirt and dust free throughout the build. Do you have any workshop tips you'd like to suggest? Leave a comment below and share your tricks with the TT community! Moto Mind - Empowering Riders from Garage to Trail http://www.DIYMotofix.com

Paul Olesen

Paul Olesen

 

Who Warms Up Their Engine Anyway?

Whenever I’m out and about either riding my motorcycle or participating in racing events occasionally I see things that just make me wonder “why”? One of those moments is when I see someone take a cold bike and fire it up for the first time and bang it off the rev limiter, start riding it immediately, or annoyingly continuously blip the throttle as if it will never idle on its own. These actions beg the question, “Why is it important to warm up an engine”? The answer lies in a simple explanation of science and mathematics. Before you quit reading because you may not have been an ace at math and science in high school, just give me a minute to break it down. It is actually really simple. The whole reason we need to let our engine warm up revolves around the concept of linear thermal expansion. Your engine is made up of a number of different materials. The piston is made from a certain type of aluminum alloy, the cylinder another type of aluminum alloy, the rings cast iron or steel, the valves if you have a four-stroke from steel, stainless, steel, or titanium, and the guides are made from yet another material. Once the engine is started these components begin to heat up from combustion and friction as they slide back and forth. None of these materials are exactly alike, and because of this they will expand when heated or contract when cooled at different rates. This interaction between material and change in temperature is predictable and linear. Now that we understand that engine components change dimensionally from when the motor is cold to when the motor is warm we can start to see the importance of warming up the engine. When a cold engine is first started the piston heats up and expands first. Heat is transferred from the piston to the rings and then to the cylinder wall. If we rev the engine and generate lots of combustion cycles and increase the frequency of friction too early the piston will grow much faster than the cylinder. If there is not adequate space between piston and cylinder to account for this growth the engine could suffer what is known as a cold seizure and you will have yourself a bad day. By allowing your engine to warm up before you start riding you allow all the components in the engine to slowly expand and stabilize. Once the engine is warm, changes in the engine part dimensions are less drastic and there is much less risk of damaging the engine. The picture below shows an engine which was limped home after the coolant started leaking out. As the engine lost its ability to cool down, things began to tighten up. You can see how the piston contacted the cylinder evenly around the bore and created the vertical scuff marks. Even though this engine didn’t completely seize, you can imagine the severity of scuffing would be much worse for an engine that would seize. So you are probably wondering, “how do I know when my engine has properly warmed up then?” and, “what exactly do I do to properly warm it up?” The procedure for warming up the engine is simple. 1. Start the engine using the choke if necessary 2. Once the idle comes up due to the choke turn the choke off 3. Allow the engine to idle with the choke off until the cooling system warms up and the engine comes up to temperature. Knowing when the engine is ready to ride is a bit subjective. As you begin to pay closer attention to your engine, you will begin to detect when it is ready to ride. Personally for water cooled engines I like to feel the radiator and use that as an indicator. I place my fingers on the side of the radiator where the coolant is returning from the cylinder head and lightly touch to get an idea of how warm the coolant is. I do this until the radiator is just getting uncomfortable to touch. This typically only takes a few minutes and after that I’m ready to start riding the bike. For air cooled engines my approach is much the same except I feel the cylinder and head to determine when I think the motor is warm enough to ride without causing any unnecessary wear or damage. Paul If you'd like to follow my blog, click the "follow this blog" button in the upper right. I'd love to have you.

Paul Olesen

Paul Olesen

 

Who the Heck is Paul Olesen?

Who the Heck is Paul Olesen and Why is he Writing for Thumper Talk? I’m really excited at the opportunity to start blogging because I’m finally going to have an outlet to express my passion for picking flowers, going for walks, and singing songs. I can’t imagine anything more exciting than doing these three things except... maybe, just maybe, riding motorcycles. On second thought, riding motorcycles and figuring out how engines work is definitely much more thought provoking and certainly what I came here to discuss... so lets get started! Most of you are probably wondering who the heck I am and what am I going to talk about. By day I’m a powertrain engineer at an American sportbike manufacturer where I work on and oversee multiple facets of engine development and production. At night I focus on my personal projects, hobbies, family, and whatever else might interest me. Since the age of 18 I’ve lived and breathed motorcycles. I’ve raced multiple disciplines (everything from road, ice, trials, salt flats, and hare scrambles), built my own racing bike, designed my own engines, modified a handful of bikes, and most importantly- made a whole lot of mistakes. These experiences, failures included, have put me in a position to teach you a few new things or at least give you an interesting read. My powersports story started at a young age, however thanks to parental restrictions I was never able to own a bike until I was 18. Once 18 hit, I promptly bought a 1984 Honda Nighthawk 700 from my high school. The bike had been donated by a member of the local community and I had my eye on it for years as I watched students try unsuccessfully to make it run right. Thanks to my never-ending curiosity, that bike very quickly got rebuilt, and to the dismay of my parents, it got ridden a hell of a lot. Shortly thereafter I graduated high school and then attended the University of Minnesota, where I was slated to follow in my father’s footsteps and become a dentist. I don’t recall too many times where I had actually thought that this career path was going to become a reality, so naturally my interest in higher education dwindled at an alarming rate. Simultaneously my interest in motorcycles was at an all time high. I was fascinated by the old Kawasaki two-stroke triples. I had never before seen a two-stroke in a motorcycle and their simplicity, light weight, and abundance of power drew me to them. In a twist of Craigslist-fate a deal for a pair of 1975 Kawasaki H2s popped up in Dallas. Before I could fully rationalize the consequences of skipping an exam, I was on my way with a friend to pick these basket cases up. On my way down to Dallas it hit me that without knowing what I wanted to do with my life, continuing going to school was pointless. I promptly quit two years into my college education, yet again much to my parents’ dismay. I had always made money running a painting business in the summer, so I did that for awhile to make ends meet. While painting has never been a glamorous business it was quite profitable and an important part of my life as it taught me the basics of running a business, allowed me the freedom to set my own schedule, and I learned how to deal with and manage people. Restored 1984 Honda Nighthawk 700 and Restored 1975 Kawasaki H2 The following year my parents ordered me back to school, this time to give engineering a try. I felt like a fish out of water. The idea of being stuck in Minneapolis for another four years brought upon visions of offing myself once and for all. A week in- I quit. I knew I needed a plan if I was going to break the news to my parents. Over the weekend I put on my big-boy pants and started searching for something that I might actually want to do with my life. Low and behold- if you Google “motorcycle engineering” a couple programs pop up in the United Kingdom. That was it, suddenly I was staring my future right in the face, a future that I actually wanted to pursue. Somehow I convinced my parents that going to Wales and attending Swansea Metropolitan University was a good idea, I applied, and got accepted shortly after. Finally I was going to go learn about something I actually wanted to, travel the world, and get a degree in motorcycle engineering. The move to Wales was exhilarating and things really started to take off for me once I began my studies. The structure of the program, the way in which the coursework was carried out, and class sizes were all a lot different than I had expected- but in a good way. The first year was a cakewalk, but it allowed me ample time to learn CAD programs, design a couple fictitious bikes, make friends, and enjoy the Welsh countryside. Towards the end of the year I decided I would design and build my own motorcycle, which I would then intend on racing in the Central Road Racing Association’s club racing events at Brainerd International Raceway in Minnesota. To keep costs down and the project manageable, I decided to build a super mono powered by a Kawasaki KX500 two stroke engine. Initial Chassis Layout My first summer back home I promptly ordered materials for the project and got back to work running my painting business to fund it. The only problem was that I had no mill, no lathe, no pipe bender, and no TIG welder- nor did I know a lot about using any of these aforementioned tools. Suddenly it hit me, there was going to be a steep learning curve. After befriending some locals who were enthused about my ambitious project as I was, in one fell swoop I procured the rights to use all the equipment I required at the odd hours I was intending on working on this bike. It was as if the universe had aligned for the things I had wanted all along as soon as I started asking for them. Quickly I got the jigs made for the frame and swingarm, enlisted the help of my father to work on the fiberglass components, and devised a plan to try and extract more power out of the engine. The biggest hold up that summer was having to teach myself how to weld. That exercise took roughly a month of practice on thin walled tubing and a hefty sized chunk of my own melted skin before I felt proficient to proceed to tackle a real frame. Fortunately, or unfortunately depending on how you look at it, I cocked up the frame design by trusting a friend’s engine model. My first go around at a frame didn’t end up fitting anything, but I got plenty of extra welding practice! By the end of summer the bike was 85 percent complete and I was able to finish the rest of it up over the Christmas and Easter breaks. Super Mono Construction My second year of school was much more engaging academically and focused a lot more on the powertrain side of things which was great. I learned all sorts of useful things to help me along with my race bike build and it was great to be so close to people that could answer some of my questions from a professional standpoint. My first test ride over Easter break came late one evening and to my dismay, it was a disappointing affair. I came back from the ride and my hands and butt were numb from all the engine vibration. Half the bike had rattled loose and the other half the hardware was completely missing! My first real world encounter with engine balancing was about to take place. Much to my dismay, simply changing the balance of the crankshaft did not in fact move the vibration to a more tolerable direction. I needed another solution. After much problem solving, I decided to try and graft on a counter balance assembly I designed to cancel out some of the forces that lead to engine vibration. This proved to be a difficult task with my amateur machining skills, but through much trial and error I managed and the balancer worked! Finishing up the balancer assembly After my second year of school I was offered a job at S & S Cycle for the summer as an engineer. This was great since I got to hang out/pester a lot of smart folks to help me with my race bike project. I learned a lot about machining, manufacturing, and engineering processes at S & S, plus the people there were awesome. My proudest moment while working at S & S was designing and building the land speed fairing for their Bonneville Salt Flats racing bike. This was a time consuming and messy affair, but it paid off when we took the bike out to Bonneville and set four land speed records! Once work was finished for the day, more often than not I went over to my bosses house. He had a decent size shop with a dyno, a hefty amount of tools, and the usual machining equipment- all the things I was requiring to make my world go round. Towards the end of my second year of school I had designed a fuel injection system which I was adamant about implementing onto my bike. That whole summer I spent my time incorporating the system into the engine and learned how to tune the engine on the dyno. By the end of summer my bike was ridable, and I was spending more and more time out on the road test riding. I had hoped to take it to the track for the final race of the year, but other engine problems cropped up and I, along with the bike, ended up staying home. My third and final year proved to be the most time consuming, educational, and one of the most exciting. As part of my degree, I was required to come up with a major project to work on and complete throughout the year. Seeing as my race bike needed a new engine, I began figuring out how to design a new single cylinder two-stroke which would incorporate all the beneficial things that I had learned over the past summer testing the KX500 engine. I settled on designing a 400cc single cylinder counter balanced engine that would use as many common parts as possible with a current production dirt bike transmission. Due to the fact that we actually had a couple Honda CRF450 bikes in the school’s workshop, and parts were cheap and cheerful, I decided to use the gearbox along with a few other parts from that engine. The rest of the engine I designed from the ground up. By the end of my third year I was calling my friends at S & S to help me out with some 3D printing so I could test fit the engine into my frame and the CRF frame. As most almost graduated grads, I was nearing the time where I needed a job, and I didn’t have any spare money to spend on having parts made so the 400cc single project had to be put on hold. 400cc prototype test fitment Job hunting proved to be an interesting time in my life, and even though I didn’t necessarily want all the jobs I applied to, I learned an awful lot through the interview process. I was able to see how companies were run, what real world engineers did, and how engineering roles were divided. Very quickly I began to determine what I did or didn’t want in a workplace and I began to wonder what my future might have in store for me. What also fascinated me was touring all of these companies’ facilities and seeing how the machine shops, engine build areas, dynos, and engineering departments were set up. One of the places I toured that piqued my curiosity the most was Mercedes AMG in the United Kingdom where the Mercedes Formula I engines are designed. I ended up going there twice for interviews and getting a job offer to work there, but thanks to work visa restrictions I was never able to secure the offer since the regulations tightened up after 2012. At that point there was really only one company in America where I thought my skill set and personality would be a good match, and that was at an American sportbike company. I had applied at the sportbike company which I was interested in in the fall of my final year and finally after four months of patiently waiting, I had heard something. An interview was arranged so I came home, loaded up my bike and prototype engine in the back of my van, and set out to East Troy. At the end of the day, after all their questions were answered, it was quite satisfying rolling out my hand built race bike in the sportbike company’s parking lot to show all the interviewing staff what I had done. The interview staff had never had another candidate who built and brought a rolling resume before and they were thoroughly impressed. Right then I realized my persistence at building my own bike had paid off and was largely responsible for landing me two jobs a lot of people dream of. I was brought on as a powertrain engineer in the fall and this is where I currently reside. Throughout my career I have continued to meet wonderful people, learn new things, and further my knowledge of two wheeled vehicles. I hope in a small way my exploits, triumphs, and failures will all be valuable lessons. Paul If you'd like to follow my blog, click the "follow this blog" button in the upper right. I'd love to have you.

Paul Olesen

Paul Olesen

 

Who Keeps Track? - Ride Logging

Do You Keep Track? How many of you regularly keep track of the number of hours or miles that have accumulated on your engine since the last time you performed any type of service on it? How helpful would it be if you had a designated place to log any riding, maintenance, and suspension tweaks? Between riding and maintenance there is an awful lot of stuff to keep track of. The last thing I want to do is complicate the matter any further by having to try and remember in my head when the last time I did some work on the bike was. So what is the best way to keep track? Having a simple ride log/service sheet is a great way to keep track of your machine’s maintenance and stay ahead of any potential problems. Another awesome device to pick up for your machine is an hour meter. Hour meters are great since they only record actual engine running time, which gives you a more realistic time value than estimating how long your engine ran while you were out on your ride. I wanted to share with you the log I use to keep track of the time I put on my bikes. Click this link to download a free copy. I have set up three versions, one for Excel users, one for Google Docs users, and a PDF that can be printed for the folks that like to document their riding on paper.   Shown below is an example of the log I keep for my YZ250. The log is simple to use and helps document basic settings, maintenance, and engine run time. I like to keep track of location and weather conditions so I can document any variation in engine performance. This is particularly useful for carbureted machines since jetting is dependent on temperature and atmospheric conditions. Once you start to build a database of information you will start to notice trends that emerge based on where you are riding and the temperature. These trends will help you determine the proper jetting for given conditions more quickly and save you a large amount time in the long run. Keeping track of any maintenance you do on the bike along with the number of hours on the engine is a no brainer. Not only will this Ride Log help you determine when certain services are coming up, it will be a major confidence boost to a potential buyer concerning your maintenance of the bike if you ever decide to sell, and ultimately help you retain a good resale value. The suspension column I will use occasionally if I make a minor tweak, however the bulk of my suspension documentation goes into a suspension log. I added this column for those of you who do not change your suspension too often. I am going to discuss suspension logging with all of you coming up soon so stay tuned. I hope that you find the rundown of the riding log beneficial and that you decide to start keeping track of your riding to improve your maintenance practices! Keep in mind I tailored this to as many of you as I could. If you want to customize it for your specific discipline, feel free. Once you get into the habit of keeping track of these things you will end up taking better care of your machine and ultimately save yourself a huge chunk of time and money in the long run. Moto Mind - Empowering and Educating Riders from Garage to Trail If you'd like to follow my blog, click the "follow this blog" button in the upper right. I'd love to have you.

Paul Olesen

Paul Olesen

 

When to Rebuild Your Engine

This week I’d like to start a long series of posts on the proper way to rebuild a four-stroke engine. I will share with you a top to bottom rebuild where I go through the disassembly, inspection of parts, and reassembly of the engine. We’ll cover the top end, bottom end, and everything in-between. I’ll pass on the tips and tricks I’ve learned over the years from the people I’ve worked with in the motorcycle industry. Hopefully these tips will benefit you on your next engine build, save you money, and ensure you do things properly. Before I get into the specifics I want to discuss the importance of preparing for the rebuild. This week let’s talk when to tear into the engine. When to replace: Engine wear is directly related to RPM and mechanical stress so riders engaging in riding where the engine is on the rev limiter frequently, the engine is operating at a high RPM without any load on it, the gearbox is loaded or unloaded abruptly, or gears are selected hastily will require the rider or mechanic to service the engine frequently. Most of you will relate the scenario I have illustrated to motocross racing. At the top levels of racing, mechanics are constantly checking or rebuilding the engines to make sure they are operating at maximum power. Fortunately for most of us we are not riding or racing at the top level, so our bikes and engines last quite awhile longer. Unfortunately everyone’s scenario is different- depending on the type of riding you do, the environment you ride in, how often the oil is changed, etc. which makes it difficult to standardize or pinpoint any sort of service interval. As an engineer, mechanic, and rider my philosophy has always been to replace components preventatively before they fail. My reasoning here is that the costs attributed with a failed component are much higher than a replaced component. Let us consider a scenario where a piston fails. This could have been avoided had I replaced the piston and would have cost around $130. Instead it’s quite likely that the entire engine will need to be opened up and serviced, making the price of the repair extremely expensive. From an opportunity point of view, if any part fails on the bike while I’m out riding or racing I’ve lost out on a significant amount of time, a significant amount of points if I’m racing, and a wad of cash when it comes to paying to get to and from the venue. So apart from saving a small amount of money by not replacing a serviceable part, there is no upside to trying to prolong the life of a component. The ramifications of engine neglect are nothing to scoff at. The best way to determine when components need to be serviced is to keep careful track of the health of your engine. This means from the time of purchase to the day you sell you keep track of all the engine hours, maintenance, and repairs you do to the bike. By keeping track of engine time you’ll start to develop patterns and be able to establish your own service intervals. I wrote a nice article about maintenance logging which you can read HERE. Along with keeping a log from day one, I also like to do a compression test any time I get a new bike so I can establish a baseline for the health of the engine. As I put hours on the bike, if I ever become suspicious that the engine is down on power I can perform another compression test. Then I can quickly refer back to my first test to determine if I have lost any compression and might need to consider servicing the top end. The next thing you must do is pay attention to your engine. In most cases your engine will give you signs that it is time to service one component or another. Some common signs that may indicate your engine is due for servicing soon are: Hard to Start - This could be due to a fueling issue, ignition issue, decompression system out of adjustment, worn rings, worn valves and seats, a stuck valve, leaking gaskets, or cam timing that is off.
Engine Power has Diminished - This could be due to restricted fuel flow in the carburetor or throttle body, a clogged air cleaner, the clutch slipping, worn valves and seats, worn rings, a stuck valve, leaking gaskets, or ignition issues.
The Top End is Noisy - A noisy top end could be caused by a loose cam chain, out of spec valve clearances, a worn cam chain guide, or worn cam bearings.
The Bottom End is Noisy - A worn clutch basket which has started to rattle, damaged or stuck bearings, a worn bushing and needle bearing between the clutch basket and primary shaft, or gears which are improperly lubricated may all contribute to bottom end noise.
Blue Smoke - Blue smoke occurs when the engine is burning oil. Either the valve seals are allowing oil to leak past them or the piston rings are no longer sealing properly. Once the engine is warm very little blue smoke should ever be seen.
White Smoke - White smoke is emitted when the engine is burning coolant. This typically occurs when a head gasket starts leaking.
The Engine Consumes Oil - Oil is getting into the combustion chamber any time the engine consumes oil. Oil can either enter into the combustion chamber from worn valve seals or worn piston rings.
The Engine Oil is Creamy - Whenever the engine oil is creamy in color moisture is getting into the engine oil. While some moisture getting into the oil is normal excessive amounts are a cause for alarm and may indicate that a water pump seal is leaking.
The Engine Oil has Large Pieces of Metal in It - Metallic particles are common in engine oil but if larger metal pieces are found in the oil this is a cause for concern and should be associated with damaged components. An example of this could be finding fragments of chipped gear teeth in oil.
The Engine Vibrates Excessively - Excessive engine vibration may be caused by an out of true crankshaft, worn crank bearings, worn counterbalance bearings, a mistimed counterbalancer, or a loose clutch.
One last tool I want to mention that is helpful in determining the health of an engine is a leak down tester. With the piston at TDC and the valves closed (compression stroke) a leak down test pressurizes the cylinder to a specified pressure. A comparison is made between how much air is supplied to the cylinder and how much leaks out. The amount of air leaking out of the cylinder is used to determine the health of the engine. For example if 70% of the air is leaking out the cylinder there are serious problems! By carefully listening for the air leak(s) it is possible to determine the cause of the problem. I would really like to help you guys out and give you quantifiable numbers so that you know precisely when the right time is to rebuild your engine however I feel that by doing this I would be doing a disservice to a lot of you. I would either be giving you information that tells you to rebuild your engine too early or too late in its life which wouldn’t be good for anyone. As I mentioned before there are so many variables ranging from riding style, engine displacement, manufacturer, riding environment, and maintenance intervals that I can’t quantify all these things into one number for everyone or even several numbers for specific groups. Your best bet is to pay close attention to your engine, keep track of the hours on your engine, and learn as much as you can about your particular make and model so that you can begin to formulate a service interval schedule tailored to you. Questions, comments, or additional tips leave a comment below! Moto Mind - Empowering and Educating Riders From Garage to Trail If you'd like to follow my blog, click the "follow this blog" button in the upper right. I'd love to have you.

Paul Olesen

Paul Olesen

 

What you really need to know about air filter maintenance

Air Filter Maintenance - What You Need To Know
In my last post I shared an account of what happens when dirt gets past the air filter and into an engine. This was a telling tale, however I want to go further and discuss key components of what can be done in terms of maintenance to limit the chances of sucking in dirt. Whether you ride a two-stroke or four-stroke, it makes no difference, the importance of keeping dirt out cannot be overstated.   I want to start off by thanking those that left constructive comments in my previous post. Your insights into filter maintenance are much appreciated and help reinforce what I’m about to share.   How often should I change my air filter?
This depends entirely on the conditions you ride in. Dusty dry conditions will warrant more frequent filter changes than a damp riding environment where dust is non-existent. The amount of dirt accumulation that is acceptable is subjective, but I always err on the safe side. As an example, my filters are blue when freshly oiled and as soon as they start to become blotchy and start to turn color I change them.   Can I change my air filter too often?
Yes and no. I say yes only because every time the filter is removed there is a chance for dirt to enter the engine. A sensible changing regimen decreases the odds of dirt getting into the engine as the filter is removed/installed.   What to Use
I’ve personally been using FFT filter oil, however, there are many great options out there. No Toil’s water based oil system is something I’ve heard good things about and would like to try too. Asking other riders or doing a quick search will certainly turn up more great options as well.   Removing the filter
The main point I want to mention here is to be careful when removing the filter from the airbox so that dirt does not come off the filter or surrounding areas and find its way into the intake. On most bikes, fitting the filter between the subframe is a tight fit and dirt can occasionally come off as the filter is pulled up.     To help prevent this, clean the subframe or any areas the filter is likely to contact prior to removing it. Also watch for dirt accumulation at the top of the filter between the sealing flange and airbox.   Airbox Cleaning
Prior to any cleaning efforts be sure to use an air box cover or stick a clean rag in the intake tract which will help ensure any dirt that is dislodged won’t make its way into the engine.   Filter Cleaning
The correct way to clean a filter depends entirely on the type of oil used. Petroleum based oils will require a two step cleaning process. First a solvent must be used which removes the majority of the dirt. Second, the filter must be cleaned in soapy water and rinsed.   Water based oils only require a one step cleaning process using soapy water or a water based filter cleaner.   Selecting Solvents for Cleaning Away Petroleum Oils
Air filters consist of multiple foam elements which are bonded together chemically with adhesives. Depending on the adhesives used in the filter, certain solvents may or may not react. If a reaction occurs, the joint can break down and the filter can be ruined.   When selecting a solvent, it is always a safe bet to follow the recommendations provided by the filter manufacturers. However, as many will point out through their own experiences, there are several potential solvents that can work in place of the manufacturer’s.   A quick forum search will surely result in an overwhelming number of hits on filter cleaning and potential solvent solutions. I personally use parts washing fluid which I've downgraded from the washer to a bucket.   Cleaning Technique
The biggest tip I can share here is to make sure you only squeeze the filter when cleaning, don’t twist it. Squeezing lessens the likelihood of the glued joints getting damaged.   Filter Oiling
The goal is to get complete uniform saturation without over oiling. This can be done a number of ways and is largely dependent on the method of application (rubbing in by hand, dunking in oil, spray on, etc.).   My preferred method is to dispense oil from a bottle and work it in by hand. I believe this process keeps the amount of excess oil at bay, isn’t too messy, and it’s relatively easy to get good uniform saturation.   Many filters have two stages, a coarse foam filter element good for trapping large particles and a fine element suited for trapping smaller contaminants. Be sure to work oil into both elements.   Remember when working the oil in to be gentle with the filter. Rub and squeeze but don’t twist.     Once the filter is saturated with oil remove any excess by carefully squeezing the filter. Ideally, very little excess oil should get squeezed out, but remember, this is entirely dependent of how generous oil was applied. After excess oil has vacated the filter a nice even thin layer of oil should be visible.   Batch
Filter oiling is a dirty job. No matter how hard I try, oil always seems to end up where I don’t want it. To make things messy less frequently, batch the filter cleaning and oiling process. Buy a few filters, oil them, use them, clean them, and then repeat the process all over again so the task isn’t done as regularly.   Keep the pre-oiled filters in Ziploc bags so that they’re ready to go when you need them.     Greasing the Flange
Is it necessary? I believe the directive to grease the flange of the filter may have originated long ago when the sealing flanges of filters were not predominantly foam. Nowadays whether grease is necessary or not is mostly personal preference accompanied by whether or not the filter cage and airbox seal flat to one another, and how tacky the oil is that is being used. Personally, I still use a waterproof grease on my filter rims, however I’m aware it is probably not necessary in all circumstances.   Installation
Keeping dirt off the freshly oiled filter during installation is the main challenge. There are a few helpful tips I can share for doing this.   First, make sure the bolt is installed in the filter cage! It’s frustrating when you forget it.   Once you’re ready to install the filter I find that rotating the filter 90 degrees to its normal direction so that it can more easily be slipped past the subframe makes things much easier. Once down in the airbox the filter can be rotated into position.     The other option is to use a plastic bag as a shield effectively covering the filter while it is being lowered down. Once in position the bag can be removed.   Wrap Up
I hope you’ve enjoyed my post on air filter maintenance. If you have any questions or comments please share them below!   For those of you interested in all things engine related check out my book, The Four Stroke Dirt Bike Engine Building Handbook for more awesome information. In honor of Independence Day we’re having a two week sale where you can save 15% by entering offer code july4th at checkout if you order before July 17th.     Thanks for reading!   -Paul

Paul Olesen

Paul Olesen

 

What Tools Do You Need To Correctly Rebuild A Dirt Bike Engine?

To continue on our engine rebuild journey I want to discuss tools this week. Use this post as a basic idea of what tools are required to do a complete engine rebuild at home. Now I know a lot of you probably have a pretty good idea of what is required, but I want this to be a quality resource for anyone just starting out and considering working on their own engine. Below I have shared all the tools required to do a full rebuild, top and bottom end, on a Honda CRF450R. Understandably each make and model will differ slightly due to parts, however I believe this example will provide a great overview of what is necessary to complete a highly thorough rebuild. In addition to the list here, I put together an Amazon wishlist of "Engine Rebuilding Tools" that you can check out by clicking HERE. I want to point out that I am in no way affiliated with selling any of these tools nor do I guarantee that you will find the cheapest prices by purchasing tools off of this list. I will take responsibility for any impulse buys and am willing to act as a scapegoat should you have to explain why you spent a load of cash to your significant other. Amazon has a very nice way of bundling all the tools into one place so you can get a feel for the individual prices. I added tools to the wishlist based on my own experience with them (I own a good portion of what's on the wishlist) and looked through user reviews on the tools I don't own. When creating the wishlist I definitely kept budget in mind, but these are not necessarily the cheapest options. This tool list is a good place start if you're looking to add to your toolbox. While some may argue or believe they need Snap-On grade tools, I believe most people can get away with a good economical set of tools. There is no-doubt that mechanics who work with their tools everyday need high quality tools, however the at-home mechanic isn't experiencing the intense workflow of a professional mechanic and will use their tools much less over time. This makes it more economical to buy lower priced tools and replace them slightly more often than the big buck tools. The trick to getting tools you'll be happy with is knowing where to spend a few extra bucks for a quality tool. I believe about 90% of all the tools you need for working on a motorcycle engine can be had pretty reasonably. The remaining 10% is where a little time spent researching good options and spending a little extra money comes into play. The 10% Final assembly tools (torque wrenches), specialty tools, and measurement tools are the three categorizes where you should look for good quality tools. Reassembling an engine or other parts with torque wrenches that are inaccurate can lead to big problems if you end up over tightening bolts, stripping threads, and damaging parts. Not investing in specialty tools which allow you to disassemble and assemble parts correctly can also lead to damaged parts. Finally, precision measurement tools are what determine if your engine components, such as cylinder and cylinder head, are in spec or need to be serviced. Measurement tools are a very special breed of tool. It takes practice to learn how to use them proficiently. If not used properly, these tools can result in inaccurate measurements. If I were just starting out learning how to rebuild engines I would seek the help of a professional machinist or builder to help with the portion of the rebuild where you need to inspect the cylinder and cylinder head. These are two of the most important parts on an engine and incorrectly assessing the condition of these parts can lead to premature failures. For builders just starting out, experience could be gained by measuring less important parts. From there you can work your way up to becoming proficient at measuring the cylinder and head. Quality measurement tools such as those offered by Starrett, Mitutoyo, and other industry leaders, can be extremely expensive for the home mechanic to buy new. There are other options such as buying used or buying brands such as Fowler, Brown and Sharp, or Anytime Tools to name a few. In my experiences the quality offered by the lower cost brands has been quite good and when I have compared some of my cheaper measurement tools to the industry standard brands they have done very well. Like all tools, measurement tools are an investment and determining if you'll get enough use out of them to warrant the cost must be determined on an individual basis. For folks just starting out I think having a a nice pair of calipers, 0-1" and 0-2" micrometers, and a set of lash gauges will do your rebuild justice. Do you have tools you want to recommend? Have something to add? Please leave a comment below. For those who have been interested, our Honda CRF450 Bottom End Full Engine Rebuild Video Manual has launched. You can check out all the details, including a preview of the video manual HERE. Moto Mind - Empowering and Educating Riders From Garage to Trail http://www.DIYMotoFix.com

Paul Olesen

Paul Olesen

 

What Spare Parts Do You Bring To The Track or Trail?

With warmer weather and the riding season around the corner for many of us, I wanted to cover a topic that can either make or break an event. Whether you’re competing in a racing series or traveling to the track or trail, let's talk about event preparedness. More specifically, what spare parts should you keep on hand? Plus, what methods do you use to keep your spares organized?

Honestly, I struggled with organization until I started working on this post. I had no method to my madness. Every time an event came up I’d do the same thing; throw a bunch of stuff in a box or the back of my van and head to the event. The sad part is I now realize this was a weakness of mine for quite some time, but didn’t do anything about it! Maybe you can relate?

I finally said enough is enough. I don’t throw my tools in a cardboard box when I go to a race, leaving what I bring to the fate of my memory. So why would I do that with the spare parts I bring?

I started solving this problem by compiling a spreadsheet detailing what spare parts I keep on hand for ice racing and hare scrambles. I realize that each discipline will differ and may have niche parts that should be kept. The goal here is not to definitively define what spares one should keep on hand, but to have a conversation and provide a resource that can be used to help people get set up based on their own needs.

Once I took inventory of everything I felt I wanted to bring to a race, I went to Menards and went hunting for the perfect organized storage bin/toolbox. Here’s what I ended up with:



Naturally, once I returned with the toolbox, my list grew and I probably need to go back for a bigger one. I intend to store a copy of the spreadsheet in the tote so I can keep tabs on inventory and know exactly what I have available.

Should I get another bike, this system is easily replicable and my plan is to get another organized toolbox that goes with it.

This system is how I went from being an unorganized “throw it in the van at the last minute” rider to a more relaxed well prepared rider. I’d love to hear how you handle event readiness, what you bring, and how you keep track of it. My hope is that by sharing our strategies we’ll save someone the misfortune of having a bad day at the track or trail. Perhaps I'll even end up with more things I need to add to my list.

-Paul

If enjoyed this post be sure to follow my blog and sign up for my newsletter!
DIY Moto Fix Newsletter      

Paul Olesen

Paul Olesen

 

What is Hard To Start

First off, happy holidays to all of you out there! Thanks for taking the time to read my blog the last few months. I hope all of you have a happy and safe holiday season! Last week I talked about when is the right time to rebuild your engine. From that post a lot of good questions were asked in the comments section and this week I'd like to take some time to address one in particular. "Can you define what is hard to start?" Like a lot of things in our sport the answer to this is a bit subjective and I will share my thoughts on the subject. As always, you're encouraged to agree, disagree, or even better- share your personal thoughts on the topic. "What is hard to start?" - This seems like a shallow question at first, but considering all the variables it is tough to answer. "Is the bike hot?", "Is the bike cold?", "Has the bike been sitting for several weeks?", "Is it carbureted or fuel injected?", "Was it just tipped over?", or "Was the float bowl just drained?". In my opinion each scenario I've proposed invokes a slightly different answer. Combine this subjectivity with one's own personal starting routine and the ease of which the bike will fire up is going to be different for everyone. As a rule of thumb, if my bike takes more than five kicks to fire up as time progresses I will begin investigating possible starting issues. "What things might make a bike hard to start but not necessarily mean the engine needs to be torn apart?" - On most bikes there are two or three things that adversely affect how well the bike will start. On carbureted bikes the pilot jet circuit controls fuel flow from idle to about 1/4 throttle. The pilot jet has a very small orifice and clogs pretty easily. Once clogged the pilot jet is ineffective in delivering the necessary fuel to the engine and starting the bike becomes extremely difficult. Depending on make and model the bike may or may not be equipped with a decompression system that can be adjusted. For example, on the Honda CRF450 in order for the decompression system to function correctly a certain amount of clearance must be maintained between the decompression adjusting screw and the rocker arm. Occasionally this system needs to be adjusted similar to how valve clearances are checked and adjusted at set intervals. If the system gets out of spec and the correct clearance diminishes, more air escapes each time the decompressor opens the exhaust valve effectively lowering the compression of the engine. Old spark plugs are another culprit which might make a bike hard to start. If the plug is old and worn the spark will be weaker, making it more difficult to ignite the mixture. Keeping fresh plugs in the engine can greatly improve the bikes starting tendencies. Temperature and altitude should also be thrown into the mix here. If for some reason you moved from sea level to 6,000ft, fueling requirements for starting will be different since the air density varies in relation to altitude. As altitude increases the density of air (i.e. the amount of oxygen in the air) decreases thus requiring leaner jetting to make the bike run correctly. Air density also varies with temperature. The warmer the air is - the less dense the air is. So if you have summertime jetting and it's now wintertime and the bike is harder to start, it shouldn't be a surprise. The colder temps require richer jets to be installed for the increased air density. "How do I start a four-stroke dirt bike?" - Another good question that has lots of answers depending on the type of bike, if it is fuel injected, carbureted, hot, or cold. I'm going to assume most of the folks having trouble starting their bikes have carbureted bikes. I will provide my personal starting strategy I use on my CRF450 and if anyone is inclined to outline their strategy or provide alternatives to mine, feel free to leave a comment and share your knowledge. When Cold 1. Fuel petcock turned on 2. Choke turned on 3. Twist throttle to wide open three times 4. Roll engine over with foot until compression stroke is found (resistance will build up under your foot as fuel air mixture is compressed and piston will then be near TDC) 5. Kick repeatedly until bike starts (usually 3-5 kicks) When Hot 1. Depress hot-start lever 2. Roll engine over with foot until compression stroke is found (resistance will build up under your foot as fuel air mixture is compressed and piston will then be near TDC) 3. Kick repeatedly until bike starts (usually 1-3 kicks) Some of you might be wondering why the throttle is twisted wide open three times and this is a great question if you're unfamiliar with the internals inside a four-stroke carburetor. The majority of dirt bikes produced in the past 10 years come equipped with a Keihin FCR carburetor. The FCR carburetor is equipped with an accelerator pump. An accelerator pump works like a fuel bulb that you might find on the small engine of a power washer or weed wipe. As the bulb is squeezed a splash of fuel is pushed out. The accelerator pump was designed into the carburetors to smooth engine operation from low rpm low load scenarios to transitions to wide throttle. As the throttle is twisted to full-open, a plunger within the carburetor is actuated and forces fuel out of the "fuel bulb" through an orifice into the throat of the carburetor. For starting, the accelerator pump can be used to prime the intake tract with fresh fuel. Does it matter if I find top dead center on the compression stroke? - It isn't critical, but this is what I'm used to and what works best for me. I hope you found this write-up helpful and if any of you want to share your experiences feel free to leave a comment. Moto mind - Empowering and educating riders from garage to trail If you enjoy reading my blog be sure to subscribe by clicking the "subscribe" button at the top right of the page.

Paul Olesen

Paul Olesen

 

What Do You Love and Hate about Today's Machines?

Today I want to shift gears, open the floor for discussion, and talk about the state of dirt biking as it relates to the bikes we buy, ride, and maintain. In my relatively short existence, a number of things have happened in the industry which has been interesting to see. A few examples, which are not by any means exhaustive of all that has gone on, include the emergence of the four-stroke power plant, electronic fuel injection, improved tire technology, electric bikes, and the development of air forks. On a more micro-level we’ve seen improvements to materials, new manufacturing processes, and coating processes which have allowed ever increasing performance. As a fellow rider and someone who has no bias or stake when it comes to manufacturers and product offerings, I’d like to hear your thoughts as they relate to today’s machines. My question to you is a simple one, are your needs as a consumer being met by today’s manufacturers and bikes?  What aspects of today’s machines do you love and what are pain points for you?  If you could do things your way, what would you change? Are there machine variants that aren’t being offered?  Leave a comment below that addresses these questions or share your historical perspective! I look forward to your responses. Thanks and have a great week!

- Paul
https://www.diymotofix.com/ 

Paul Olesen

Paul Olesen

 

What Changes In Valve Shim Size Can Tell You About Your Engine

I hope you enjoyed my last post on ice tire studding! The season in my neck of the woods has been a bit short this year and I may be getting back to the dirt sooner rather than later. Nonetheless, Part II, which covers mounting ice tires is now up on my blog. You can view it here: Ice tire mounting.   In today's post I'm going to shift focus back to the engine and talk a little about valve technology. Valve technology and manufacturing techniques have changed substantially from the earlier days of engine development and I want to share with you some information about the current valve technology being implemented in your engines. I also want to discuss one way you can get a feel for how much life is left in your valves. Let’s get started.   The following excerpt is copied directly from my book, The Four Stroke Dirt Bike Engine Building Handbook. If you want to learn more helpful tips, which will bring your maintenance knowledge and engine building skills to the next level, I’d like to invite you to pick up a copy of my book by clicking here. Be sure to use the offer code tt2016 to get 15% off when ordering!   Alright, on to valves shim sizes.   The cylinder head assembly of most engines will wear out before it resorts to telling you it has had enough by catastrophically failing. Diagnosing these wear signs and knowing when it is time to replace components is the key to keeping the cylinder head assembly from failing. Due to the aggressive camshaft profiles, high compression ratios, and high RPMs required to make a lot of power, the valves and seats typically are the first parts to wear out within the cylinder head. Worn valves and seats will cause the engine to become difficult to start, have low compression, and have reduced power.     Modern valves found in dirt bike engines are made from either titanium or stainless steel alloys. Regardless of valve material, modern valve faces are either coated in a variety of anti-wear materials or hardened using various hardening processes. Common examples of trade names you might be familiar with include diamond like coatings (DLC) and black diamond coatings. These coatings are typically harder than the base material of the valve and help the valve resist wear, which occurs from ingesting dirty air and repeatedly contacting the valve seat. Coating and hardening processes are only present at the surface of the valve face. Depending on the type of valve and process used to harden it, the coating thickness can range from as little as 0.0001” (0.003mm) to around 0.003” (0.076mm). An easy way to visualize the thickness of the coating is to pluck a hair from your head and either measure it or feel it between your fingers. Most human hairs are around 0.002” (0.05mm) which should give you a good idea of how thick the coatings used on the valves are.   The important takeaway here is that if the coating is only a few thousandths of an inch thick, the valve can only be adjusted a few thousandths of an inch before it will have worn through the coating. Monitoring the starting valve shim size once the engine has been broken in (or new valves installed) and comparing that size to the shims required the next time the clearances are adjusted is a great way to assess valve health. Normally within the first 3-5 hours of breaking in a new engine the valve shim sizes may change slightly. This is due to the mating of the new valves to the seats and any valve seat creep which may occur. After this occurs and the valves have been shimmed to compensate, usually an adjustment up to around 0.004” (0.10mm) is all that can be done before a valve has worn through its hardened surface. Once this happens the valve face will wear much more quickly and start to wear out the seat as well. This will result in more frequent valve shim intervals and necessitate the need for having the valve seats cut. By paying attention to changes in shim sizes you will be able to approximate when the valves have worn through their hardened surfaces and must be replaced.   Thanks for reading and please leave questions or comments below. I enjoy hearing from you!   Remember you can get 300 pages worth of in-depth dirt bike engine information with The Four Stroke Dirt Bike Engine Building Handbook. Be sure to use discount code tt2016 at checkout to receive 15% off your order!   -Paul   DIYMotoFix.com

Paul Olesen

Paul Olesen

 

Tips on Buying a Used Motorcycle

TIPS ON BUYING THE PERFECT USED BIKE How many of you have bought your fair share of used bikes only to discover the moment you get it home that something is wrong with it? I have bought and sold a hefty amount of different types of vehicles over the years and recently started reflecting on some of my experiences. I have bought bikes that have run well, did not run at all, were partly assembled, or were complete basket cases. Sometimes there have been great deals and sometimes there have been total lemons. Occasionally I have even purchased bikes sight unseen and put my good faith in others to collect them for me. Has some of my behavior been risky when buying a used bike? Absolutely, but because of those experiences a lot of hard earned knowledge has come my way. With all the variables that get thrown into purchasing a used bike wouldn’t it be great if there was a way to increase your chances of avoiding a lemon? Over a month ago I started compiling all my used motorcycle buying advice to share with you. Now I know most of you are experts at buying used bikes, but these guides are great because it puts everything conveniently in one place, not to mention a printable checklist you can take with in your back pocket to reference in case you forget a few things. I began by writing down everything I considered vital when purchasing a used bike. Beginning with the research phase, I gave pointers on what to look into - prior to even browsing through any ads. Next I organized all the different things that are worthwhile to look over on the bike itself. In conjunction with that, I wrote down all the questions I think are important to ask the seller. Being allowed to test ride the bike is a huge thing for me also, so I went over all the different test procedures I use when test riding a potential bike. Last, but certainly not least, I included my tactics and tips when negotiating with the seller. These tips aim at the end result of hopefully heading home with a fantastic used bike in tow. After all this writing I ended up with two 30+ page buyer’s guides - one for dirt bikes and one for street motorcycles. These guides are the most thorough and detailed when it comes to purchasing a used bike I have found. I want to share eight of what I consider the top tips with all of you in my blog and ask that you download whichever free guide you need to learn the rest as there is just way too much information to post here. KNOW WHAT YOU WANT - RESEARCH MAKES & MODELS Thoroughly researching different makes and models will go a long way to ensure you get the bike you want. Familiarize yourself with the bikes you are interested in by researching and reading reviews on the particular makes and models you're interested in. By reading the reviews you will be able to gain a better understanding of what sort of performance you can expect from particular models, their shortcomings, and some things you can do to improve these bikes. CHECK THE VIN NUMBER Look on the frame of the bike for the VIN number to ensure that the bike is not stolen. If the VIN number is scratched off or the sticker has been removed, this is an indication that somewhere within the history of the bike it may have been stolen. If you have any suspicion that the bike is not clean, contact your local authorities and have them run a VIN number check. Refrain from exchanging any money until the the history of the bike is cleared. FEEL THE MOTOR Carefully feel near the engine for heat radiating off the engine to determine if the engine has been started prior to your visit. If the motor is warm it could indicate that the bike does not start easily when it is cold and the seller is trying to mask an issue with the carburetor or fuel injection system. If it is an older bike, a potential fix would be to clean and inspect the carburetor. If it is a fuel injected bike, there could be issues with the injectors, the fuel pump, the ECU, or the ignition system. CHECK HOW CLEAN THE MOTORCYCLE AND THE ENGINE ARE Often times if there is a problem or the motor is leaking, the seller will power wash the motor to hide the leak. If the motor or bike is suspiciously clean, when the seller runs the motor for you, double check around the engine for leaks that may appear. ASK THE SELLER WHY THEY ARE SELLING? This is a great ice breaker. This questions gives perspective into the seller’s motivation and reasons for selling. It also may give a glimpse into potential issues the bike may be having. HOW MANY MILES ARE ON THE BIKE AND WHAT HAS BEEN SERVICED? The mileage on a bike can be used as a very rough gauge to determine where it is at in its life however nowadays motorcycles are designed to perform well and not require a great deal of service work even with high mileage. How well the owner has taken care of the bike, the type of riding they did, and the conditions in which it was stored are all better factors for assessing where it is at in its life cycle. Street bikes typically require service after predetermined mileage intervals established by the motorcycle manufacturer. These services may include valve clearance checks, oil and filter changes, and clutch maintenance. This question will help you gauge when and how much upcoming service work may be required. In most cases street bike engines will last a long time and not require much internal engine work if the engine is routinely serviced and basic maintenance is performed. By familiarizing yourself with some of the routine maintenance tasks for the make and model you are interested in you can gauge the frequency and scope of work which is considered routine maintenance and compare this to what the seller tells you. Keep in mind if you are looking at bikes that have been raced or are of the single cylinder variety more maintenance may be required to keep them in top shape. LET THE ENGINE WARM UP & LISTEN TO IT IDLE Allow the engine to come up to operating temperature, this usually takes a few minutes of idling. Most bike are equipped with a coolant temperature gauge which you can reference to see how warm the engine is. Listen as the engine runs for how well the bike idles. The bike should have a nice consistent idle and the motor shouldn’t be hunting or surging. Assuming the bike is carbureted and does not idle, it is likely that the carburetor needs servicing or something is out of adjustment. If the bike is fuel injected and does not idle, there could be an issue with the fuel map, pump, or injector. SHIFT THROUGH ALL THE GEARS Feel with your foot how easily the bike shifts into the next gear. You should be able to feel if the gears kick back out or do not engage easily. If the bike jumps out of gear or does not shift well, there could be problems with the gearbox. Pay special attention to the shift from 1st to 2nd gear since this is the shift that requires the biggest stroke to engage (since neutral is between them) and usually wears out first. Typical problems may include rounded gear dogs, bent shift forks, or worn shift forks. Remember if any of these problems exist you will have to split the crankcases to remedy the problem (unless the engine utilizes a cassette style gearbox or has a separate transmission). Be sure to shift through all the gears at least a few times to make sure any problems that arise are repeatable and predictable. This will help rule out any user error where the rider did not shift fully. If you like the tips shared thus far and want to learn more about navigating the slippery slopes of buying a used bike, I would encourage you to download the free guide you need, whether it is dirt or pavement. The guides come in the form of a downloadable PDF, ready to be printed and kept forever. The Buyer’s Guides also include a checklist that you can bring along and reference as you proceed through all the steps of buying a used bike. The checklist is incredibly useful when it comes to looking over the bike and inspecting individual components. I know my adrenaline goes wild when picking up a new bike and I run the risk of skipping over one or two important things, so the checklist will ensure you do a thorough job. Just click the link below to go to the downloads! Grab Your Free Used Dirt Bike or Motorcycle Buying Guide Do you have any tips that I left out of the guides? If so, post them in the comments section so everyone can benefit from your experiences! Moto Mind - Empowering and Educating Riders from Garage to Trail P.S. If you haven't subscribed to my blog yet be sure to click the "Follow this Blog" button at the right of the page!  

Paul Olesen

Paul Olesen

 

Three Easy Ways to Improve Engine Cooling

This month I want to discuss three easy ways to improve engine cooling for your dirt bike or ATV and explain why they are effective. As improvements are made to an engine that increase its power, the amount of heat the engine will create will also increase. Effectively removing heat from the engine and cooling it is very important as the power output of the engine goes up. The cooler an engine runs, the more power it can produce. There are three ways that the aftermarket attempts to improve the cooling system of a particular engine. 1. Increase flow through the cooling system. 2. Increase the cooling capacity of the radiators. 3. Increase the pressure of the cooling system. Let's dive in. 1. Increase flow through the cooling system
The flow through the cooling system can be increased by installing a water pump impeller designed to increase the flow rate of the coolant. The reason increasing the flow rate of coolant works is because the rate of heat transfer from the engine to the cooling system is directly proportional to the mass flow rate of coolant. This is thermodynamics jargon, but there are two key parts to consider. First, how much coolant is flowing, and second, at what speed the coolant is flowing. The more coolant that flows and the faster it flows will reduce the temperature difference between the point where the coolant enters into the engine and where it exits. This next part is not quite as intuitive. When the temperature difference between the inlet and outlet is reduced, the average coolant temperature is lowered. When the average coolant temperature is lowered the engine will run cooler. This is why fitting a water pump, which increases the flow of coolant through the engine, improves cooling. 2. Increase the cooling capacity of the radiators
Radiators consist of a series of tubes and fins which run from the top to the bottom of the radiator. These are often referred to as the radiator’s cores. As coolant enters the radiator it moves through the series of tubes and heat is transferred from the coolant to the fins. Air passes over the fins and heat is transferred from the fins to the air. This transfer of heat from coolant to air is how radiators reduce the temperature of the coolant. Coolant temperatures can be reduced by upgrading radiators in three ways, by increasing the frontal area of the radiators, by making the radiators thicker, or by using materials with better heat transfer properties for the cores. For all practical purposes, increasing the radiators’ frontal area and improving the core materials is rarely a viable option for dirt bike applications. This is because there is little room for the radiators to begin with and they are susceptible to damage, making the use of expensive core materials a risky affair. Unfortunately, both of these options are better improvements to make before resorting to increasing the thickness of the radiators. Increasing the thickness of a radiator is not as efficient of an improvement as increasing the frontal area of the radiator. In order for thicker radiators to cool more effectively than their stock counterparts, airflow past the radiators is key. When the thickness of a radiator is increased, air must travel a greater distance through the radiator before exiting. The speed the air is traveling plays a big role in determining how quickly the air heats up as it moves through the radiator. If the air is not traveling fast enough through the radiator, the air temperature will rise and equal the coolant temperature before reaching the end of the radiator. Once this happens, heat transfer stops and whatever portion of the radiator remains will not help with cooling. In order for a thicker radiator to be effective, air must flow quickly enough through it so that the exiting air temperature is at, or better yet, below the coolant temperature. In conclusion, benefits from adding thicker radiators will be more prominent in applications where speeds are relatively high. Whereas in applications where the bike is hardly moving, improved cooling may not be noticeable. 3. Increase the pressure of the cooling system
The last alteration to the cooling system that can be made is to install a high pressure radiator cap. As coolant temperature increases, pressure increases inside the cooling system. The radiator cap is designed to be the pressure release point in the cooling system in the event that too much pressure builds up. This can occur as a result of overheating or a blown head gasket for example. By designing the radiator cap to be the weak link in the system, other parts of the system, such as seals, don’t end up getting damaged from being over pressurized. The radiator cap features a plug and spring on its underside. The spring is designed to compress once a certain pressure is reached, at which point the plug will move upwards and uncover a pressure release hole where excess pressure will be vented.



The coolant’s boiling point and ability to conduct heat are necessary factors in understanding why a high pressure radiator cap can help improve engine cooling. Water alone boils at 212°F (100°C) while a 50/50 mix of water and antifreeze boils at 223°F (106.1C). Radiator cap pressure designations are usually advertised in bar, with most stock radiator caps designed to withstand pressures up to 1.1 bar (16psi). The more pressure a fluid is under, the more difficult it becomes for the fluid to vaporize, and the higher its boiling point becomes. When water is under 1.1 bar of pressure, the temperature water will boil at is 260°F (127°C) while a 50/50 antifreeze mix will boil at 271°F (133°C). By installing a radiator cap designed to withstand higher pressures, an additional increase in the coolant’s boiling point will be seen. High pressure caps are usually designed to withstand 1.3 bar (19psi) of pressure. This 0.2 bar (3psi) increase in pressure over the stock system will increase the boiling point of water or antifreeze by 8.7°F (4.83°C). This will then bring the boiling point of pure water or a 50/50 antifreeze mix to approximately 269°F (132°C) and 280°F (138°C) respectively. While this small temperature increase alone won’t do a lot for your engine, coupling a high pressure cap and using coolants with better heat transfer properties can do wonders. Antifreeze (ethylene glycol) alone is not an inherently good conductor of heat. In fact, pure antifreeze conducts heat about half as well as water, while a 50/50 mix of antifreeze and water conducts heat approximately three quarters as efficiently as pure water. This means a cooling system using a 50/50 mix of antifreeze would have to flow faster than a cooling system filled with pure distilled water in order to achieve the same cooling efficiency. What this means for you is significant cooling gains can be made by using distilled water and an additive called “Water Wetter” in place of an antifreeze-water mix. Water Wetter is an additive that improves water’s “wetting” abilities (another whole subject), adds corrosion resistance, and slightly increases the boiling point of water. A high pressure radiator cap in conjunction with distilled water and Water Wetter as the coolant is by far the best route to go for high performance applications where freezing is not an issue. For applications which must still be resistant to freezing, the antifreeze-water ratio can be altered in favor of mixtures incorporating more water than antifreeze so that the cooling efficiency of the mixture is improved. Just bear in mind the freezing point of the mixture as it is thinned with water will be reduced, so you will need to pay close attention to the environment you are operating in so that the coolant is never susceptible to freezing. A frozen coolant system can ruin an engine and makes for a very bad day! I hope you enjoyed this post on three easy ways to improve your engine’s cooling.  One more thing before I wrap up! April is Autism Awareness month, and here at DIY Moto Fix we couldn't be more excited to announce that we will be donating 15% of all profits made in April to AutismMX. If you haven't heard of AutismMX, this amazing non-profit brings Autism awareness to the motorcross community. Founder, Matthew Dalton, created this non-profit after finding that motorcross was an amazing way to connect with his autistic son. At DIY Moto Fix this non-profit also touches a chord with us. Our filmmaker and photographer, Kelsey Jorissen, loved dirt biking with her autistic brother throughout their childhood. The Autism MX Project focuses on four areas: Autism MX Day Camps are days for ASD kids and families to have the chance to ride AMX’s little dirt bikes and quads and enjoy the sport of motocross. Team Autism MX Sponsoring amateur MX racers, riders as well as sponsoring AMA pro racers. Through doing so, they are getting out the word on Autism Awareness to millions. AMX Puzzle Piece Apparel from shirts, graphics, goggles, to help stand out and support Autism Awareness. AMX Ride Days for Autism Awareness AMX celebrates Autism Awareness and is a fundraiser for The Autism MX Project. So for the entire month of April - if you buy a book, a video, even a poster - 15% of that purchase will go towards AutismMX and their amazing cause. Thanks for reading and have a great rest of your week!

Paul Olesen

Paul Olesen

 

The Two Stroke Dirt Bike Engine Building Handbook is Here!

In today's post, I'm very excited to share details about my new book,The Two Stroke Dirt Bike Engine Building Handbook. As with all of my blogs and technical resources, my goal has been to bring riders clear and concise technical information. My two-stroke book exemplifies this and puts nearly 300 pages of engine building knowledge at your fingertips.

I wroteThe Two Stroke Dirt Bike Engine Building Handbook to be an all-encompassing guide on engine building. From the moment there is doubt about the engine's overall condition to the time the rebuilt engine is broken in, I give you a step-by-step guide to help you work towards a successful build. My aim was to create a definitive resource that hit on all the relevant topics you'll encounter as you proceed through an engine build and take any guesswork out of the equation.

Throughout the book, engineering knowledge and practical experience are fused together to detail the how and why behind the way procedures are performed, parts are designed, and engine performance is affected. This is the most important and valuable aspect of the book, and it's something you won't find in a service manual. The book doesn't just tell you to bolt part A to part B, it teaches and explains the correct way assembly procedures should be performed and why it is necessary to do so. It also explains the intricate relationship between parts, where to look for wear patterns, and shows examples of worn and damaged components.



If you're interested in making modifications to your engine or if you're curious about how certain modifications affect performance, I wrote an entire chapter dedicated to the subject. Within this chapter a discussion on how performance parts such as expansion chambers, port timing modifications, and cylinder heads alter overall engine performance is included and helpful suggestions are provided to aid you in choosing the correct components for your build, depending on your specific riding needs.

If you have a thirst to learn more about how your engine works and a desire to correctly disassemble or assemble an engine to professional standards, you will benefit greatly from this book. Whether a complete beginner or a seasoned builder, with nearly 300 pages and 250 images worth of information, there is fresh and useful knowledge for everyone. There is also valuable material packed into this handbook that doesn't just pertain to the act of building the engine. I include instruction on diagnosing engine problems, sourcing and determining which parts to replace, using precision measuring tools, setting up your workshop, and additional tests and inspections that should be performed when preparing racing engines. If you just want to build your engine back up to stock spec, you are covered. If you want to go the extra mile and prepare a racing engine, you are also covered. In a way, this book allows you to choose your own ending by giving you all the tools and knowledge you need to complete your build at whatever level you decide. As a way to thank you for your support, we're offering TT members 15% off during a special TT pre-sale which runs from now until December 5th (when the book officially launches). Simply follow this link to learn more and order: ThumperTalk Pre-Sale

Thanks again for all your support as we've grown DIY Moto Fix from an idea to a thriving community of riders who are passionate about making their machines perform better through their own hard work. Thanks for reading and have a great week. -Paul    

Paul Olesen

Paul Olesen

 

The Top 6 Characteristics You Need To Have To Rebuild An Engine

I hope you’re all having a good fall and are getting excited for the holidays. It snowed for the first time this year here in Wisconsin and I’m getting eager for the lakes to freeze over so I can get out and ride the ice. I need to set aside a good 7 hours to stud my tires and set up my bike before that can happen though!   Today I want to talk about six characteristics that are necessary to have when one sets out to build an engine. I’ve detailed how to tackle many different jobs, but honestly that is only half the battle. If you’re in a rush or lack the desire to understand the reasons behind what you’re doing, you will make mistakes and miss out on important things. Listed below are the traits that I believe can help you take your build to the next level.   1. Being Detail Oriented
What’s worse than getting started on a build only to realize you didn’t buy an important replacement part? Focussing on the details of a project can feel tedious at times but can pay off in the grand scheme of things. Before I get started on a project I spend a hefty amount of time researching what parts I’m going to replace and where the best prices are. Also, I will have a solid idea of the sequences I’ll use for disassembly and assembly. Another good habit for the detail oriented is to take notes throughout the build, which you can use at a later date should the need arise. When you have an appreciation for all the small details that go into a build, it will make for a much smoother project.   2. Having Patience
Have you ever been in a rush to do something and after you’re done you realize if you had spent just a bit more time the project could have turned out much better? I was this way with so many of the things I did when I was younger, but have learned to slow down and be patient as I work. Engines don’t go together instantaneously and being patient throughout the process, especially when things aren’t going as planned, is very important. There is nothing worse than making a huge mistake because you’re in a rush. Imagine finishing a build and realizing you left an important part on the table, depending on where the part came from, you just bought yourself another few hours of work. Trying to skimp on time more often than not costs you more time in the long run. Have patience and enjoy the process.   3. Being Observant
Just about every mechanical thing is gleaming with a story, and that story only reveals itself if you know what to look for. An engine is no different. From the parting lines on a component left by the casting tooling used to create it to wear patterns on a piston, there are hundreds of observations that can be made while working on an engine. As you work, keep an eye out for subtle anomalies that may tell you why something failed or broke. For example, things like snail tracks across a gasket, raised edges on gasket surfaces, or covers that don’t sit flat on a table - these are all good indicators of why a particular part was leaking.   4. Being Curious
Perhaps more appropriately titled, “a desire to understand mechanical workings”. It is incredible how much can be learned about the engine just by studying how specific parts interact within it. An engine is composed of many different subsystems and they must all work in order for the engine to function. By looking at the various interactions of the parts within an engine, the condition of the parts and reasons for any failures can be more easily understood. The next time you build an engine, challenge yourself to learn how all the different subsystems of the engine work. Once you learn this, diagnosing problems and identifying all the faulty parts becomes much easier.   5. Being Meticulous
The necessity to be thorough and meticulous throughout a build cannot be overstated. Whether it be taking extra steps to inspect components, measuring new parts, or taking extra time to ensure the condition of surrounding subsystems are okay, having meticulous tendencies can pay off. As an example, on more than one occasion I’ve purchased new parts that have been mispackaged or out of spec. Had I not made the choice to carefully measure the problematic new parts, I could have ended up with an engine that was destined to fail. While it may take more time to be meticulous throughout a build, there is a lot at stake, both in terms of time and money, making it all the more important to ensure everything is done correctly.   6. Having Ambition
Building an engine can be hard, things can go south unexpectedly, and projects can easily stall. Being ambitious and having a can-do attitude is important to ensure the engine doesn’t sit half torn apart in the garage never to be completed. Until you tear into the engine, you never know what you might find. I’ve disassembled engines many times in the past only to find I need to replace a lot more parts than I had planned (this seems to be my luck when I shop for bikes on Craigslist as of late). This can be a huge downer, but keeping the end goal of getting back out and riding in mind and having the desire to push through any and all obstacles is a must.   Do you have any engine building characteristics you want to share? Leave a comment below and tell everyone what you think it takes to build a great engine!   For those of you that believe you possess the characteristics of a good engine builder, be sure to check out my book, The Four Stroke Dirt Bike Engine Building Handbook, to learn more about the how and why behind engine building. Whether you want to be taught about the relationships between all the various parts within an engine, you are in need of pointers on picking the right performance parts, or you would like to see examples of wear patterns found on engine components, my book is here to guide and help you throughout your build.   With the holidays coming up, I want to extend a special four day offer to you for the handbook and all the other products at DIY Moto Fix. Between November 27th and November 30th if you purchase anything from DIY Moto Fix you will save 30% on your order. If you’ve got a significant other trying to do some holiday shopping for you, be sure to send the site their way before Monday the 30th  
Save 30% and check out the book and other products by clicking this link: DIY Moto Fix

Paul Olesen

Paul Olesen

 

The Top 5 Specialty Tools

The Top 5 Specialty Tools Today I wanted to start a discussion about the top specialty tools that every home mechanic should have in their shop or garage. I picked out my top five most important specialty tools and encourage you to add your favorites to the list by leaving a comment. The top five I have selected are critical for engine building and in my opinion the job cannot be done right without them. Torque Wrenches Believe it or not, every nut and bolt on your machine has a torque specification associated with it so that you do not run the risk of over tightening, damaging the fastener, or leaving something too loose. Even simple things, like the bolts holding your plastics on and your seat down, have torque values that you should aim to follow. While you might not get into trouble if you overlook using a torque wrench on these fasteners, I consider everything in the engine torque wrench territory. In order to build a good sound engine it is critical to follow the manufacturer's suggested torque specifications for all the fasteners and use a good quality torque wrench. On a four-stroke engine I would say the single most important thing to torque properly is the cylinder head nuts or bolts, depending on the model you have. If you over tighten it is very possible that you could strip something whether it be the nut, the bolt, or the crankcase threads. Ultimately if you overlook it or do it incorrectly, you have created additional work for yourself and taken a step backwards. Now let's assume you under-tighten the cylinder head. This won't result in a favorable outcome either. Your cylinder head gasket and base gasket both require a certain amount of pressure to compress them properly so that they seal. If you under-tighten your cylinder head the gaskets may not seal correctly and you may end up with coolant in your combustion chamber, coolant leaking out around the cylinder head, a cooling system that blows coolant due to the combustion pressure pushing it out, or oil leaks around the base gasket. In other words- bad news for a healthy engine. Usually the range of torques you will need to cover will require you to pick up a couple different wrenches. Right now I've got a small one that goes from 30-150in lbs for the delicate stuff and a larger wrench that goes from 20-100ft lbs. As for what brand is the best, everyone seems to have their favorite, but I personally like the wrenches CDI offers. CDI is a branch-off company of Snap-On and they offer great quality at less cost. I paid around $100 a piece for my wrenches, which came with all the necessary calibration paperwork I like to see. Flywheel Puller If you have to split crankcase you will have to remove the flywheel. I have heard stories and seen video footage of folks beating off their flywheels, but I definitely would not recommend this tactic. Picking up a flywheel puller for your specific model so you can do the job right is a much better option. The pullers are fairly cheap, easy to use, and make the job extremely easy. Strap Wrench The strap wrench is a great versatile tool. My favorite spot to use it is on the flywheel when I'm removing the flywheel nut. In order to remove the flywheel nut you will need to secure the crankshaft in some way. A lot of people will lock the crankshaft from the clutch side so they can remove the flywheel nut, but in my opinion this is not the best practice. If you lock the crankshaft on the clutch side and apply torque to the flywheel side, the crank will tend to twist around the crankpin. This may not be a huge problem when loosening the nut, but when you reinstall and torque the nut you run the risk of twisting the crankshaft. If you do end up twisting the crank you can expect expedited engine wear, excessive vibration, and main bearings that will not last long. Again, not good news for a healthy engine. Clutch Basket/Sprocket Holder The clutch basket holder locking pliers are truly the only answer for properly disassembling and assembling clutches. In the past I have seen screwdrivers jammed into the hub to keep them stationary while trying to tighten or untighten the nut. This sort of thing typically ends with damaged clutch parts, meaning more cost to you in the long run. The clutch basket holder locking pliers are great because they can be adapted for pretty much any size clutch hub and provide a solid means to retain the hub while fastening the nut. The pliers are fairly inexpensive at around $30 and some even double as sprocket holding pliers. Crankcase Splitter Splitting crankcases should be a delicate procedure, especially if the crank is to be reused, and having a crankcase splitting tool on hand makes the job a lot easier. I have seen videos of people beating on the end of the crank to push the cases out, but I assure you this is not the right way to do it and may put the trueness of the crank in serious jeopardy. The case splitter is a must-have and provides a way to evenly and gently separate the cases. Along with the other tools listed, the crankcase splitter is relatively cheap and will pay you back handsomely by helping you perform a top quality trouble-free build. I hope you guys agree with my top five specialty tool picks. Leave a comment with your favorite tools and why! Moto Mind - Empowering and Educating Riders from Garage to Trail

Paul Olesen

Paul Olesen

 

The Four Stroke Dirt Bike Engine Building Handbook

I hope all of you have been getting out on your bikes and riding as much as possible now that spring is in full effect. For those of you in warmer climates, please don't remind me you have been riding year round without any additional layers, this only makes me jealous and forces me to seriously consider the thought of moving. I've been very busy the past month, but have tried to get a couple hours in on the bike every Saturday. There truly is no better therapy than going out and spanking the bike around after a long week of work! I'm very excited to announce that the eBook I have been working on these last four months, The Four Stroke Dirt Bike Engine Building Handbook, is officially released. I want to spend a little time talking about what the book has to offer you as a dirt bike engine building enthusiast; I don't think you will be disappointed. Below is a snapshot of the table of contents as well as a few interior pages, just to give you an overall look at what this book covers for you. What could this book possibly be about that other reference materials, like service manuals, don't already cover? I wrote The Four Stroke Dirt Bike Engine Building Handbook to be an all encompassing guide on engine building. Whether you are building a stock or performance engine, this book provides a specific framework for you to understand and use throughout the entire process. From the moment there is doubt about the engine's condition to the time the rebuilt engine is broken in, I give you a step-by-step guide to help you work towards a successful build. My aim was to create a definitive resource that hit on all the topics you may question as you proceed through an engine build, and teach you the how and why behind the way things are done. I've been very fortunate to work with talented engineers and builders over the years. This book is a way to share the knowledge I have learned from them with you, a way to bridge that gap for at-home engine builders to enable you to be better equipped with the proper insight and information when it comes time to rebuild. Today's modern four-stroke dirt bike engines are fine pieces of engineering, are designed to exacting tolerances, and require a great deal of care and precision in order to keep them operating at their finest. If you don't work with engines on a regular basis or haven't been taught by a great mentor, there are a lot of subtleties which can be overlooked that I've written extensively about for you. Throughout the book, engineering knowledge and practical experience are fused together to detail the how and why behind the way procedures are performed, parts are designed, and engine performance is affected. This is the most important and valuable aspect of the book, and it's something you won't find in any service manual. The book doesn't just tell you to bolt part A to part B, it teaches and explains the correct way assembly procedures should be performed and why it is necessary to do so. It also explains the intricate relationship between parts. For example, the interaction between the valve guides, seats, and valves must be understood in order to understand why valve seat cutting shouldn't be left to just anyone. Along with the practical building how and why, an entire chapter has been dedicated to detailing how performance parts affect engine performance. Within this chapter helpful suggestions are provided to aid you in choosing the correct components for your build, depending on your specific riding needs. If you don't work directly with engines on a regular basis, it is hard to acquire practical experience when it comes to diagnosing problems and detecting abnormally worn parts. Not knowing what to look for when inspecting engine components can lead to improper diagnosis and assembly of an engine, which could still have bad parts in it. I have filled the book with as many photos and written examples of worn or damaged parts as I could so that you will know exactly what to look for when inspecting engine components as you proceed through the build process. This is invaluable practical knowledge, which only comes with experience, and is not something you will find in your service manual. Now that you have a general feel for what the book is about you may have more questions. One I've been asked a few times now by friends and fans is how can you write a book applicable to all makes and models? Believe it or not, the variations of dirt bike engine designs between manufacturers are in truth very minimal. Sure, there are physical and locational differences. One brand may use two camshafts while another uses a single cam, or one may put an oil pump on the left side of the engine while the other puts it on the right, but the overall layout of the engines and function of the parts are all similar. I did not write this book with the focus being on the little differences between brand X and brand Y. I wrote this book outlining specific techniques and inspection points applicable to every type of engine you will encounter. The function and the way components interact does not change just because they are physically different or located in different places. This is imperative to understand in order to get the most out of the book. To ensure I've covered the various ways parts interact and can be assembled, I've used two different engines throughout the book as examples and have provided specific instruction on how to deal with assembly differences that will be encountered across the Japanese and European brands. If you have a thirst to learn more about how your engine works and a desire to correctly disassemble or assemble an engine to professional standards, you will benefit greatly from this book. Whether a complete beginner or a seasoned builder, with over 300 pages and 250 images worth of information, there is fresh and useful knowledge for everyone. There is also valuable material packed into this handbook that doesn't just pertain to the act of building the engine. I include instruction on diagnosing engine problems, sourcing and determining which parts to replace, using precision measuring tools, setting up your workshop, and additional tests and inspections that should be performed when preparing racing engines. If you just want to build your engine back up to stock spec, you are covered. If you want to go the extra mile and prepare a racing engine, you are also covered. In a way this book allows you to choose your own ending by giving you all the tools and knowledge you need to complete your build at whatever level you decide. The book is available in both print and eBook format. We ship worldwide and offer door to door tracking for overseas shipments. I also created a discount code just for the ThumperTalk community that gives you another 20% off the list price. Be sure to enter the code thumpertalk2015 before purchasing. Order the print book directly from our website or on Amazon. You can order the eBook directly from our website and it will immediately be sent to your email inbox. From there you can download it to your electronic device of choice to read or print. You also have the option to just view it online.  This is one tool you can add to your toolbox that won't wear out and break on you and can be used universally. Thank you for your support of DIY Moto Fix these last few months, and enjoy the heck out of the book! Thanks for reading guys and have a great week. -Paul Olesen DIY Moto Fix - Empowering And Educating Riders From Garage To Trail

Paul Olesen

Paul Olesen

 

School Has Started - Are You Ready For What's Next?

School Has Started - Are You Ready For What's Next? Recently I have had a few of the younger forum members send me messages thanking me for sharing my personal story, technical advice, and being so open in my blog. A few of these folks have shared with me how they are struggling a little bit right now in university, whether it be with difficult classes, professors that aren’t open to supporting unique projects, or their expectations are just not being met. I figured if these folks reached out to me, there must be a few other young people in the community with some of the same thoughts on their mind. Since it wasn’t too long ago when I was dealing with similar situations, I thought it might be a good idea to share some of my advice regarding attending a university and landing the dream job you want afterwards. And what better time to address some of these issues than at the start of a new school year? Your Senior Year of High School and “Deciding” on Your Future I remember my senior year of high school well. My life mostly revolved around sports and I certainly didn’t pay enough attention to what I was going to do after I graduated. My parents made it clear that I would be attending college, however I had no idea what I would go for because I had absolutely no clue what I wanted to do for the rest of my life. College football was truly the only option I figured I could pursue. Unfortunately that dream quickly disappeared after I tore my ACL in a pickup basketball game right at the dawn of my collegiate career. In my opinion doing well academically and participating in extracurricular activities is essential to giving oneself the best chance of getting into a specific university you have your eyes on. If you’re unsure of what you want, at least keep the door open for future opportunities. The academic side of school I used to strongly dislike. The classes were boring and I thought that I would never utilize the things I was learning, however in the back of my head I knew that if I didn’t do the best job I could I would be closing some future doors prematurely. All young adult woes aside, I knew deep down that nothing would suck worse than missing out on an opportunity because I didn’t do as well as I could have. Figuring out what to do after high school is tricky. Some know right away and some it takes quite a bit longer to figure out. Taking your time isn’t something to be frowned upon though I believe. It took exactly two motorcycles alongside two years of studying pre-requisites to become a dentist before I realized that all I ever honestly thought or cared about was motorcycles. Even after this realization it took me another entire year of life experiences and research before I could figure out what my next step might be. I checked out programs to become a mechanic, I checked out machining programs, and I even went back to college for a week to do a general mechanical engineering degree. At the end of that frustrating week I took to Google and finally found what I actually wanted out my professional life, a degree specifically for motorcycle and powertrain engineering. My future became instantly clear and I knew exactly what I wanted to be doing. The reason I am sharing this journey with you is so it can be understood just how long it can take to figure out what you want out of life. While it might be nice to have some magical switch flip towards the end of high school and instantly know what you want to do, this often isn’t the reality. With the cost of tuition on the rise, my advice to anyone considering university right after high school would be to get as much exposure pertaining to the thing you think might want to do before you make that final decision. Whether it be job shadowing, working a relative job, or interviewing someone in the field you’re interested in - these are all good actions to take before saying “yes”. If you’re very uncertain of what you want take a few general courses, spare your wallet a full tuition, and get a feel for the things. Nowadays it might be more beneficial to take some time after high school and work in a field you’re interested in, explore a bit, and gain new life experiences before committing a serious amount of time and money to a degree. Getting the Most Out of University and Landing a Job You Actually Want Once you’re on a chosen career path, either academically or in the workplace, do not expect the road to the top to get easier. There has never been a time in history where more people are coming into the workforce with degrees and credentials. This has caused the competition for jobs to be fierce. The harsh truth is just because you might end up with a degree doesn’t mean you will end up with a job immediately after you graduate. In order to land your dream job or get on the path to attaining your dream job, you will have to DO more than your peers. This could mean anything from joining a student led project/organization (think Formula SAE), working on a unique project yourself, interning/volunteering in a relative field or a combination of all of these things. It always helps to work on things you’re interested in, the things you are passionate about. Once I finally got started on the education I truly cared about, it was pretty easy to be enthusiastic about working on projects outside of the required coursework. As a motorcycle guy I wasn’t interested in cars so participating in the student run Formula SAE program was not a very good option for me. I knew I had to create my own projects that would push me, challenge me, force me to grow and make mistakes on my own. For the first two years of university I worked on something purely because I wanted to, because I knew I would learn a lot from it, and I knew it was unique and would set me apart. That first year I designed my own racing motorcycle and proceeded to build it over the course of my school breaks. My second year I wanted to learn more about fuel injection and tuning, so I implemented a fuel injection system on to my racing motorcycle’s two-stroke engine. Finally, in the third year I got to work on designing a two-stroke engine for my racing motorcycle, and as a bonus I got graded on it as it was my final year project. I strongly believe that because of these additional efforts I made outside of my work in the university, I was able to attain the dream jobs I desired after graduating. So take action, work on something because you love it, because it peaks your curiosity, and do it for yourself. You might just find that these efforts outside of school are the projects that turn heads in the industry. The Networking Side While choosing a career in a field you’ll enjoy, working hard, and making yourself stand out are all essential - I feel the practice of networking is equally as vital. In high school I was extremely shy and in college and had to work hard at being more outspoken. By pushing myself to speak my mind, ask questions, and start conversations I was able to make some amazing connections. In all my experiences good things happen when you start interacting with people who share similar goals, hobbies, careers, or other things. Often times these interactions occur randomly and you never know at the time what a conversation may lead to. I can fully attribute getting my first job to networking. I grew up in a small town and my dad was the local dentist. One of his patients was a Bonneville racer, Tom Anderson. Tom attended the speed trials every year. He introduced the two of us and I was given the opportunity to go out to Bonneville and help out as a mechanic for his racing team. Tom was an excellent networker. He had the gift of gab and seemed to be friends with everyone in the pits. Towards the end of the week George Smith from S & S Cycle came to the event and Tom introduced me to him. I was a bit nervous but ended up asking Mr. Smith if there were any opportunities to intern at S & S and he kindly gave me his card and asked me to get in touch with him after the races. Shortly after I emailed Mr. Smith, went to S & S for an interview, and got my first job there for the summer just before starting my final year of university. Had I not gone out and connected with Tom and Mr. Smith I think the chances of getting an internship at S & S would have been much slimmer. It always helps for people to put a face with a name and I encourage all of you to work on growing your network throughout your academic careers and into your professional lives. I hope you’ve found my advice on academics, jobs, and networking to be beneficial and wish everyone in school or just starting their career the best of luck with your future! Moto Mind - Empowering and Educating Riders from Garage to Trail If you'd like to follow my blog, click the "follow this blog" button in the upper right. I'd love to have you.

Paul Olesen

Paul Olesen

 

Save The Salt

I want to switch gears with this post and bring your attention to an issue that is near and dear to myself and many land speed racers. Over the past decade salt mining has caused track conditions at the Bonneville Salt Flats to become worse and worse. Years ago, the salt layer was up to 5 feet thick, today it is less than an inch in some places. Salt mining is partly to blame for the depletion of salt at Bonneville and holding racing events there is becoming extremely hard!   I know not many of you here on TT may participate at, or have ties to Bonneville, but this is great opportunity to band together as powersport enthusiasts and help out those that do. Please help your fellow motorheads by signing the following petition which asks for salt mining to stop at Bonneville. I've signed and hope you do too!   Save the Salt Petition   The salt flats at Bonneville are a special place and it would be unfortunate to not preserve them for future generations. Thanks everyone!   Paul  

Paul Olesen

Paul Olesen

 

Riding Year Round in The North

ICE RIDING We're pretty excited up in the North that the lakes are frozen over. That means we can get the ice bikes out and start the winter riding season! We shot a short film over the holiday weekend detailing one of the two days we were out riding. I hope it makes you consider getting into the sport of ice riding or racing, because it's freaking awesome. WHAT YOU'LL NEED TO GET STARTED: Tires: Racing studs are classified into two categories, AMA screws which have a head height of 0.189" and Canadian screws which have a head height of 0.250". The difference between the two screws is that the Canadian screws with the taller heads grip better, especially when there is a layer of snow on top of the ice. Racing organizations in the US are starting to incorporate classes for Canadian screws, however racing classes mandating AMA screws are still predominant. For this reason I advise anyone just starting out and thinking about racing to start out on AMA screws so that more options are open later on if you decide to start racing. Tires can be bought studded or you can stud the tires yourself. Ice tires typically consist of the tire itself, the studs, and an inner liner which protects the tube from the ends of the screws. There is some technique behind studding the tires. Screw head orientation and insertion angle are important for traction and tire longevity. Kold Kutter has a nice video detailing how to install ice screws, which you can view below. For more detailed info on screws you can visit the Kold Cutter website. For professional tires I recommend Jeff Fredette's tires as they are what I have been running the past two years and can attest to the quality and traction they deliver. There are plenty of other reputable businesses studding tires as well, but Jeff's tires are my favorite. Jeff's tires can be found at: FPP Racing. Fenders: Fender kits can be bought or you can design your own fender setup using minimal tools and supplies. In my opinion any time you're riding in close proximity to other bikes, fenders are mandatory because they protect yourself and others from accidental tire to tire contact. When ice tires from one bike bind into another the result is catastrophic and unpleasant for both rider and bike. I'm sure you can imagine. The fenders ensure any tire contact between bikes is eliminated and the worst that will happen is the grinding away of the fender. Suspension: For the weekend rider and beginning racer, running stock suspension is pretty common. Shortening the shock and forks to lower the bike up to five inches is fairly common for serious racers because it lowers the center of gravity and makes the bike easier to handle. The suspension can also be softened slightly to help the bike adhere better to the ice when ruts and braking bumps form mid-race. Two-Stroke vs. Four-Stroke: Either a two-stroke or four-stroke bike can be a formidable weapon on the ice, however there are some differences I have found between the two. Due to the effects of four-stroke engine braking at times corner entry seems a little more difficult and entry must be assisted with modulation of the rear brake to help tip the bike in.
The free wheeling nature of the two-stroke allows for a little more natural corner entry.
Four-stroke bikes are a little more forgiving when entering a corner in the wrong gear and are more capable of tractoring out of the corner.
450cc size four-stroke and 500cc size two-strokes wear out tires faster than smaller displacement machines.
Two-stroke bikes have a lighter feel to them.
Four-strokes are a little more forgiving when tuning for cold weather than two-strokes.
Staying Warm: Ice riding provides a very good workout and staying warm isn't too hard if you use a little common sense. As with any cold weather activity layering up is essential. I like to wear thick socks, compression shorts, knee pads, and then a pair of sweat pants over the top for my first bottom layer. On top I wear a long sleeve compression shirt followed by my elbow and shoulder pads, then my chest and back protector. Next I wear snow pants, motocross boots, and my winter jacket. Around my face I wear a balaclava as well as a breath deflector inside my helmet to help keep my goggles from fogging. I equip my bike with handlebar mitts which allows me to wear a pair of regular motocross gloves. The handlebar mitts make or break the riding experience and with the mitts I've been able to get away with thin gloves down to around 5 degrees F. Racing: Racing typically consists of GP style tracks with both right and left hand corners, or oval tracks. GP races are either short sprint races or long three hour endurance races. One of my favorite races is the 3 hour Steel Shoe Fund race held in Cambellsport, Wisconsin. Last year over 75 teams entered the endurance race and all the proceeds went to aid injured flat track racers. Whether racing or spectating, this is definitely an event worth checking out. Steel Shoe Fund Race For finding races and riding spots local to your area I've found Google to be a powerful tool. Do a little digging and you are sure to turn up some quality riding or racing. Or if you are lucky enough to live on a lake, let the ice get up to 6 inches thick, plow a track, and have at it. I hope you enjoyed my break down of ice riding and if you have more info to share, a race you want folks to know about, or want to show off your ice bike please leave a comment. Together we can help grow and bring awareness to this awesome sport! Moto Mind - Empowering and educating riders from garage to trail If you haven't already done so be sure to follow my blog by clicking the button in the top right hand corner.

Paul Olesen

Paul Olesen

 

Premix Once - Measure Twice

Premix Once - Measure Twice I cringe when I see someone guess at the proper amount of oil to mix with their fuel when filling up their two-stroke dirt bike, snowmobile, jet-ski, or even weed whip. Manufacturer’s spend an awful lot of time figuring out what the right amount of oil is for a given engine application so when I see someone add a splash here and a splash there and call it good it worries me. If you’re one of those folks maybe after reading this it will worry you too. Adding too little oil may lead to improper lubrication of the crank bearings, rings, piston, and rod bearings causing premature failure due to excessive wear and increased friction. You might think using less oil will save you a few dollars, will lead to more horsepower, or will keep your spark plug from fouling. Let me assure you that buying another quart or gallon of oil is much cheaper than having to replace an entire top and/or bottom end. Personally I have not come across a single study that proved less oil lead to more horsepower. I have ran oil mixtures as rich as 20:1 and have not had any problems with the bike fouling plugs. In my opinion, plug fouling occurs from poor combustion (possibly caused by combustion chamber shape, spark strength, or ignition timing) not the amount of oil in the mixture itself. Let’s consider the effects of having an oil mixture that continually varies each time the bike is filled with fuel. As an example let’s say that the bike and carburetor is set up to run at a fuel/oil ratio of 40:1. What happens if we get generous with the amount of oil we add when we fill the bike up? Let’s say after we finish filling we end up with a fuel/oil mixture that is 20:1. Now the bike has much more oil in the fuel mixture than there was originally. There is no question that the engine will be well lubricated, but will the engine perform better or worse? Assuming that no changes are made to the carburetor to account for the richer oil mixture, the engine will most likely run worse. The reason being the amount of fuel able to pass through the orifice of the main jet, pilot jet, and needle circuit is reduced due to dilution caused by more oil. This will cause the bike to run lean and may lead to problems! While you may think you are doing the engine a favor by giving it more lubrication, unless the carburetor is adjusted to compensate for this change, you are actually increasing the chances of doing damage to the engine by running it lean. On the flip side we could decide to take our engine that is set up to run a 40:1 fuel/oil mixture and use less oil. Let’s say we are down to the last quart of oil and need to get a couple bikes through a weekend of riding so we skimp and run the bikes at 80:1. In this case the opposite will happen. Since there is less oil in the fuel/oil mixture, more fuel will be able to flow through our carburetor circuits, thus causing the bike to run rich. A rich bike is much better than a lean bike, but what if there is no longer enough oil to adequately lubricate the engine? If there isn’t enough oil to lubricate the moving components within the engine, it is highly likely that engine components will wear faster, run hotter, and ultimately fail. My advice to you would be to take the extra five minutes every time you mix to measure out the amount of gas and oil precisely. That way each time you fill the bike up you are giving your engine the most consistent fuel/oil mixture possible. Taking the time to do this will lead to more consistent performance, maintenance intervals, and save you a lot of money on an avoidable rebuild. If you don’t already have an oil measuring container go out and pick one up for a couple bucks and throw it in with your riding supplies so you are never in the situation where you have to guess. Another tip I want to share with you is when you are at the gas station filling up your container with premium, let the first gallon of fuel go to your car or truck. By doing this you purge the gas pump’s hose of whatever blend was previously dispensed and ensure you are in fact getting premium for your toys. Once done filling and mixing, I like to label my gas jugs with the date I mixed them and with the fuel/oil mixture I mixed. Doing these simple things will help avoid confusion down the road and a keep your engine healthy. Moto Mind - Empowering and Educating Riders from Garage to Trail If you'd like to follow my blog, click the "follow this blog" button in the upper right. I'd love to have you.

Paul Olesen

Paul Olesen

 

Precision Measuring For The At-Home Mechanic // Part 3

As we wrap up our final post on precision measuring for the at-home mechanic, I hope you have found this three part series on measuring helpful and informative. If you need a brush up or haven't gotten a chance to read Part 1 or Part 2, we compiled all three parts into a free guide for you. You can download your free copy by clicking here. This three part series comes right out of the book I published, The Four Stroke Dirt Bike Engine Building Handbook. I think you're going to love the in-depth knowledge and information provided in this book on four stroke dirt bike engine building. To learn more and order your copy click here. In this post I will be covering the final six precision measurement tools you have at your disposal. Each measurement tool in this post features a description of appropriate applications for the tool and a step-by-step tutorial on how to use it. This post is designed as a reference so that you can easily come back to it at any time as you become more comfortable using measurement tools during a rebuild. PLASTIGAUGE Plastigauge is one of the only measurement tools you won’t mind throwing away once you are done using it. Plastigauge is a measurement tool used to check the clearance between parts. The plastigauge consists of little strips of plastic which are inserted between two parts. Once assembled the plastic strip is compressed. The amount the strip compresses can be measured and correlated to a chart (supplied with the plastigauge) which defines the clearance for the measured compressed width of the strip. For engine building purposes plastigauge is ideal for checking clearances between engine components utilizing plain bearings. The plastigauge is a great tool for confirming clearance and measurements. Another plus is that unlike most other measuring tools, plastigauge is cheap! Plastigauge is usually sold in an assortment of sizes which cover multiple clearance ranges. Plastigauge strips will come in different diameters and each diameter will be capable of measuring a certain clearance range. Where to Use: Examples include cam to cam journal clearance, crank bearing to crankshaft journal clearance, and crank pin to rod bearing clearance. Calibrating Plastigauge Finally a measurement tool where no calibration is necessary. Just make sure you choose the appropriate size strip for your application. Also make sure the plastigauge is fairly new. Plastigauge does get old after awhile and using old plastigauge may not yield accurate results. Reading Plastigauge After the plastigauge has been compressed use a calipers to measure the width of the compressed strip. Record the width in your notebook. Then look at the clearance chart provided with the plastigauge to determine the clearance that corresponds to the measured width. Yes, it really is that simple. How To Use 1. Clean the parts being assembled 2. Insert a small strip of plastigauge between the parts being assembled. 3. Carefully lower the mating part down onto the plastigauge. Take great care to lower the part straight down so the plastigauge doesn’t move. 4. Install the fasteners used to secure the parts together. 5. Tighten the fasteners to the torque value recommended by the manufacturer. Follow any special tightening patterns that may apply 6. Carefully loosen the mated parts. Again, follow any special instructions for loosening provided by the manufacturer. 7. Remove the part. Check to see which part, if any, the plastigauge has stuck to. 8. Use a calipers to carefully measure the width of the plastigauge. 9. Refer to the chart provided with the plastigauge to determine the clearance which corresponds to the measured strip width. Tip: With a keen eye taper and out-of-roundness can also be spotted by using plastigauge. Keep an eye out for variations in strip width after it has been compressed for clues about the condition of the bore. DIAL INDICATOR A dial indicator measures variations in height by utilizing a plunger which travels up and down. As the plunger travels a dial gauge records the amount the plunger has moved. For engine building purposes a dial indicator is a handy tool to have when measuring valve lift and finding top dead center. There are a wide range of dial indicators on the market. Choosing the best one for engine building may be daunting if you’re not familiar with them. There are two main features you want to look for when selecting an indicator. The amount of travel the indicator has and the resolution of the indicator. Choose an indicator with around 1.0” (25mm) of travel which has a resolution of 0.001” (0.025mm). This type of indicator will work well for engine applications. In addition to the indicator getting a few accessories for the indicator will be beneficial. Most indicators are not sold with a base. Magnetic bases are really handy when setting the indicator up and provide a means of securing the indicator so it can’t move. Even when working with aluminum parts (ex. cylinder head) a magnetic base can be utilized by bolting a flat piece of steel to the aluminum part. Dial indicators usually come equipped with rounded contact points which are ideal for measuring flat surfaces. Occasionally you may encounter a setup which requires a different contact point. A variety of contact points are offered for indicators and having an assortment never hurts. Tip extensions are a must have if you plan on doing any deep depth work with the indicator. One situation which routinely requires a tip extension is when using the indicator to find top dead center of the piston. Tip extensions can be bought in multiple lengths. Where to use: Examples include measuring valve lift, and finding top dead center. Reading Dial Indicators Reading a dial indicator is very similar to reading a dial calipers. The only difference is the dial indicator’s gauge face is equipped with a second smaller dial face. For an indicator with a resolution of 0.001” the small face is divided into 10 graduations. Each graduation represents a tenth of an inch. The outer dial face is divided into thousandths of an inch. Each time the outer needle rotates one revolution around, the second small needle tallies a tenth of an inch. This eliminates the need for the user to keep track of how many times the needle has gone around. The total measurement is comprised of the number of tenths of an inch the smaller needle is indicating plus the number of thousandths the large needle is indicating. In the picture above the dial indicator reads _0.136". For metric and other resolutions of dial indicators the reading process is identical to the above. Take note of the units and resolution and proceed to read the indicator accordingly. Calibrating Dial Indicators Checking and adjusting the accuracy of dial indicators usually can’t be done easily in one’s own shop. For dial indicator calibration the indicator would have to be sent to a calibration lab. Fortunately, the applications an indicator is used for when building engines doesn’t require the utmost accuracy so calibration is seldom a problem. How To Use: 1. Clean the contact point of the indicator and the part which will be indicated. 2. Carefully set the indicator up so that it is fixed to a sturdy base which can’t move. 3. The amount of travel in each direction you will need depends on the specific application you are measuring. Consider the motion and travel of the part you want to measure and set the indicator accordingly so that it doesn’t run out of travel halfway through measuring. For example, when measuring valve lift you would want to engage the indicator so that around a quarter of the plungers travel has been used. 4. Square the spindle of the indicator being measured. The more square the indicator spindle is to the part the more accurate the readings will be. If the indicator is set at an angle to the direction of travel of the part the indicator will not read accurately. Keep this in mind and always try to set the indicator spindle as square as possible to the part being measured. 5. Zero the indicator by rotating the gauge face so the outer needle aligns with “0”. For example when measuring valve lift the zero point would be when the valve is fully closed. When checking runout the zero point may be a low or high point. 6. Move the part being indicated a few times returning it to its starting position each time. Check to make sure the indicator consistently reads “0”. If it doesn’t then carefully adjust the gauge face to realign the needle. 7. Once the indicator has been zeroed proceed to move the part being indicated and take measurements. 8. After measuring return the part to its original position. Occasionally an indicator can get bumped or something can happen during the procedure. This is a good way to confirm one last time that the indicator is still zeroed. DIAL TEST INDICATORS Dial test indicators are very similar to dial indicators, however their primary function is more as a comparative tool than a measurement tool. The main difference between a dial indicator and dial test indicator is the dial test indicator uses a contact point which pivots instead of a plunger that travels up and down. This pivoting action results in an arcing path instead of a straight up and down path. The test indicator is best suited for taking comparative measurements and zeroing runout. For engine building purposes this makes a pair of dial test indicators well suited for measuring the runout of a crankshaft. Just like dial indicators, test indicators are made with different lengths of travel and different resolutions. The most suitable resolution for crankshaft truing and inspection purposes is 0.0001” (0.0025mm). Most test indicators with a resolution of 0.0001” will have a travel of 0.008” (0.203mm) or 0.010” (0.254mm) which will be suitable for crankshaft inspection. The test indicators will require fixturing so having a pair of bases, stands, and clamps is necessary. Fortunately, the test indicators use similar mounting systems as dial indicators so if you have fixturing for dial indicators you are all set to mount the test indicators. Where to use: Examples include crankshaft inspecting or truing. Reading Dial Test Indicators The gauge face of a dial test indicator is symmetrical. The face is divided into graduations based on the resolution of the test indicator. Each side of the face represents half of the total travel of the test indicator. Reading the gauge is simply a matter of determining how many graduations the needle has moved from its starting point to its ending point. Calibrating Dial Test Indicators Like dial indicators, calibrating dial test indicators is usually done by a professional calibration lab. As long as the test indicator is well cared for the need for calibration should be infrequent. How To Use: Since the contact point of the test indicator travels in an arc the way the indicator is set up has an impact on measurement. This is the main reason test indicators can’t be relied on heavily for taking measurements and instead are used for comparing. 1. Clean the contact point of the indicator and the part which will be indicated. 2. Carefully set the indicator up so that it is fixed to a sturdy base which cannot move. 3. Most test indicators function best when the contact point is perpendicular to the direction of travel of the work piece. Some indicators differ slightly and should be set at a slight angle, so confirm with the instructions supplied with your test indicator to attain the correct orientation. 4. The majority of test indicators work best when the contact point is preloaded. As a rule of thumb a 1/10 - ¼ revolution of the needle is about right for setting preload. Instructions supplied with individual indicators may have specific preload instructions. 4. Rotate the part to find the high or low point. Zero the indicator by rotating the dial face so the needle aligns with “0”. 5. Move the part being indicated a few times returning it to its starting position each time. Check to make sure the indicator consistently reads “0”. If it doesn’t then carefully adjust the gauge face to realign the needle. 6. Once the indicator has been zeroed proceed to move the part being indicated and take measurements. 7. After measuring return the part to its original position. Occasionally an indicator can get bumped or something can happen during the procedure and this is a good way to confirm one last time that the indicator is still zeroed. TRANSFER GAUGES Transfer gauges are measurement tools which don’t yield a direct measurement. They are simply tools which can be used to transfer the dimensions of something requiring measurement to a measurement tool. There are two types of transfer measurement tools commonly used in engine building, small hole gauges and telescoping gauges. Transfer gauges can be tricky to use accurately for a couple reasons. First, they introduce a second source for error. Instead of taking a direct measurement the measured part must first be sized using a transfer gauge. Then the gauge must be measured by a measurement tool such as a micrometer. It is easy to see how mistakes can accrue in this situation. Second, transfer gauges rely heavily on feel to obtain accurate measurements. If the user of the gauge is unskilled, the transfer measurements could be all over the board. Taking these points into consideration transfer gauges can still be incredibly helpful when measuring engine parts. Transfer gauges are one of the most relied on methods of accurately measuring internal diameters. SMALL HOLE GAUGES Small hole gauges are used to transfer internal measurements usually less than ½” in diameter. A small hole gauge has a split in its head which allows the head to expand or contract to the size of the part being measured. An adjustment knob at the end of the handle is turned to expand or contract the head. The head on the gauge can either be a full or half sphere design. The half sphere designs have the advantage of being able to measure blind holes. Small hole gauges are usually sold in sets capable of measuring from around 0.125 - 0.500” (3.175 - 12.4mm). Each set is comprised of around four gauges with each gauge being able to measure a certain portion of the set’s total range. For engine building purposes, small hole gauges are primarily used to measure the inner diameters of valve guides. Where to use: Valve guides How to use: 1. Clean the bore of the part to be measured and the head of the small hole gauge. 2. Slowly turn the adjustment knob on the gauge expanding the head of the gauge inside the bore of the part being measured. 3. Simultaneously, gently rock the gauge back and forth and fore and aft inside the bore until the head of the gauge just starts to drag on the bore of the part. As you rock back and forth make sure the handle of the gauge passes through the point where the handle is square to the bore. 4. Remove the gauge. 5.Use a micrometer to measure the diameter of the gauge to determine the diameter of the part’s bore. Since the gauge can easily be compressed little to no pressure can be applied by the measuring faces of the micrometer. 6. Slide the gauge back and forth and fore and aft as you delicately tighten the ratchet or thimble of the micrometer. An accurate reading will be obtained when the micrometer just starts to drag against the gauge. Remember to measure perpendicular to the split in the gauge. 7. Lock the the spindle of the micrometer and read the micrometer to obtain the bore diameter. Hot Tip: Since this is partly an exercise of feel, take multiple measurements until the measurements start to yield the same results. This way you can be certain the measurements are accurate. TELESCOPING GAUGES Telescoping gauges are the big brothers of the small hole bore gauges. Telescoping gauges are shaped like a “T”. A tightening knob is situated at the handle end and it controls one or two spring loaded plungers (dependent on gauge type). Once the knob is loosened the plunger(s) expand outwards to capture the diameter of the bore being measured. The plunger ends are convex so the gauge can be rocked back forth to obtain the measurement. Telescoping gauges are usually sold in sets capable of measuring from around 0.3125 - 6.0” (8 - 152.4mm). Each set is comprised of around six gauges with each gauge being able to measure a certain portion of the set’s total range. Where to use: Examples include lifter bucket bore and cylinder bore. How to use: 1. Clean the bore of the part to be measured and the ends of the plungers on the telescoping gauge. 2. Set the gauge inside the bore with one plunger touching the side of the bore. 3. Slowly loosen the adjustment knob on the gauge handle expanding the plungers of the gauge inside the bore of the part being measured. http://www.thumpertalk.com/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=231329 4. Set the gauge up so that the handle is just out of square with the bore. 5. Tighten the adjustment knob down. 6. Gently wiggle the gauge back and forth while passing the gauge through the bore. Only pass the gauge through the bore once. This will center the gauge and set the plungers to the diameter of the bore. http://www.thumpertalk.com/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=231330 7. Clean both measuring faces. 8. Use a micrometer to measure the diameter of the gauge to determine the diameter of the part’s bore. Since the gauge can be compressed, little to no pressure can be applied by the measuring faces of the micrometer. 9. Slide the gauge back and forth and fore and aft as you delicately tighten the ratchet or thimble of the micrometer. An accurate reading will be obtained when the micrometer just starts to drag against the gauge. [series of pics showing measurement direction 10. Lock the the spindle of the micrometer and read the micrometer to obtain the bore diameter. Hot Tip: Since this is partly an exercise of feel, take multiple measurements until the measurements start to yield the same results. This way you can be certain the measurements are accurate. V-BLOCKS A V-block is a large precision machined metal block with a V in it. During an engine build V-blocks are used primarily for checking runout of cylindrical parts such as the crankshaft. http://www.thumpertalk.com/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=231331 When shopping for V-blocks a precision ground matched set should be purchased. Fancy versions may come with magnetic bases, multiple Vs, clamps, or rollers. While some of these features are nice they certainly aren’t necessary and add to the cost. That wraps up our three part series on precision measuring for the at-home mechanic, thanks so much for reading! If you would like all this precision measuring information in one place so you can come back and easily reference it, we created a free guide for the ThumperTalk community that you can download right to your computer or phone. Click here and I'll email the The At-Home Mechanic's Guide To Precision Measurement right to you so you can have it organized in one place. If you are interested in owning a copy of The Four Stroke Dirt Bike Engine Handbook, you can learn more by clicking here. Thanks again for reading and feel free to leave a comment below! -Paul Olesen DIY Moto Fix | Empowering And Educating Riders From Garage To Trail.

Paul Olesen

Paul Olesen

 

Precision Measuring For The At-Home Mechanic // Part 1

This week I want to provide you with some in-depth knowledge on the world of precision measurement. As at-home mechanics who want to take their rebuilding skills to the next level, learning about precision measurement and how to properly use precision tools is the final frontier. This post comes right out of The Four Stroke Dirt Bike Engine Building Handbook, the engine building book I am currently writing for my fellow riders who want to bring their engine building skills into a professional realm in their own garage. This post is part one of three that will cover the correct use and implementation of precision measurement tools when rebuilding your own engine. The world of measuring is so complex by nature that one could get wrapped up writing an entire book on the subject and still not cover it all. This is not my intention with my engine rebuilding book. My aim is to provide you with the principles on how measuring works, what the most important takeaways are on the subject of measuring, and an overview of how to use the tools correctly. Once informed you can then delve further into the intricacies of measuring for your own needs. There are three terms that are important to the fundamental understanding of measurement. These terms are often mixed up, confused as meaning the same things, or used incorrectly. These terms are accuracy, precision, and resolution. Understanding these three terms will go a long way in ultimately understanding measuring and the capabilities of measurement tools. ACCURACY Accuracy is how close a given measurement is to the “true” value of an object. For example, if a valve stem was exactly 0.1969” (5.000mm), accuracy would quantify how close the measurement tool was to the true value. PRECISION Precision is a measurement of repeatability. For example if an object was measured five times, precision would quantify how close the five measurements are to one another. Another way to think of precision is the finiteness of which a measurement tool can be read repeatedly and reliably. RESOLUTION Resolution is the smallest distinguishable value of a measurement tool. If a ruler is divided up into tenths of an inch then the resolution of the ruler is one tenth of an inch. A micrometer that can be read to one ten thousandth has a resolution of one ten thousandth of an inch. Just because a measurement tool, such as a micrometer, has a very fine resolution doesn’t mean it will be accurate or precise to that resolution. This will be explained more shortly. Distinguishing the difference between accuracy and precision is most easily done with a set of pictures. Four scenarios can occur when measuring. A measurement can be both accurate and precise.
A measurement can be accurate but not precise.
A measurement can be precise but not accurate.
A measurement can be neither accurate nor precise.
It is imperative when measuring engine parts that the measurements are both accurate and precise as represented in the first picture. Precise and Accurate Accurate but not Precise Precise but not Accurate Neither Precise nor Accurate Now let's see what happens when the bullseye is taken out of the picture: Notice that if the bullseye is taken out of the picture there would be no way to reference if the shots were accurate? It would be easy to tell that the “accurate but not precise” and “neither precise nor accurate” scenarios didn’t yield meaningful results. However, the scenario with “precise but not accurate” results could be misleading for someone measuring. This is exactly why it is important to calibrate measurement tools before using them. By calibrating a measurement tool you ensure it is accurate prior to measuring an unknown object. What Affects Accuracy and Precision? Now that the key parts of accuracy, precision, and resolution have been outlined how do they apply to measuring tools and measuring? I want to go over three factors that lead to variation in accuracy and precision when working with measurement tools. 1. Type of Tool and Tool Quality Different types of measurement tools will have different ranges of accuracy. For example a digital 0-6” calipers is usually accurate to 0.001” (0.025mm), however it will have a resolution of 0.0005” (0.0127mm). Just because the resolution is 0.0005” (0.0127mm) doesn’t mean that is how accurate the tool is. For a 0-1” micrometer the accuracy is 0.0001” (0.0025mm) and so is the resolution. Be sure to keep accuracy and resolution in mind when using and shopping for measurement tools. Decent measurement tools should have the manufacturer’s accuracy specified in the tool description. Using a calipers to measure the bore of a cylinder is a good example of using a measurement tool which is not accurate enough for the task at hand. Most dirt bike cylinder bores have a diametric range in the neighborhood of 0.0006” (0.0152mm), taper limit of around 0.0004” (0.0102mm), and out of round limit of around 0.0004” (0.0102mm). A calipers is off an order of magnitude in accuracy and is not capable of doing the job. 2. Temperature The temperature a measurement is taken at can have a large effect. A standard has been set for the temperature parts are measured and inspected to in the engineering and metrology worlds. That standard temperature is 68°F (20°C), which is what you should strive for when you are precision measuring parts. The reason temperature is important is due to the concept of thermal expansion. In a nutshell thermal expansion explains how an object’s volume will change as temperature changes. As volume changes so does length, which is what matters in this case. Equations for linear expansion will be used to show the role temperature plays on the diameter of a cylinder bore at two extremes: 32°F (0°C) and 100°F (37.78°C). Consider a cylinder that has a bore of 3.7795” (96.000mm) - typical of a 450cc engine. At 68°F we will say the cylinder measures exactly 3.7795” (96.000mm). What happens when the same cylinder is measured at 32°F (0°C) and at 100°F (37.78°C)? Let’s work it out. The formula for linear expansion is: ∆L = α x D x ∆T where: ∆L = Change in diameter of the cylinder bore α = coefficient of thermal expansion for aluminum (13.3 x 10^-6) in/in °F D = original diameter of the cylinder ∆T = Change in temperature (Final Temperature - Initial Temperature) α = (13.3 x 10^-6) in/in °F D = 3.7795” ∆T = 32°F - 68°F = -36°F Now it all gets put into the equation and solved. ∆L = (13.3 x 10^-6) in/in °F x 3.7795” x -36°F = -0.0018” ∆L = -0.0018” (0.046mm) So the 3.7795 inch cylinder has now shrunk to 3.7777 inches (95.954mm). A 36°F (20°C) change in temperature has caused the aluminum cylinder bore to change by 0.0018” (0.046mm)! In terms of cylinder measurements this is a big change and illustrates just how important it is to measure engine components in the right environment. A similar change can be seen when the cylinder is measured at 100°F (37.78°C). α = (13.3 x 10^-6) in/in °F D = 3.7795” ∆T = 100°F - 68°F = 32°F Now it all gets put into the equation and solved. ∆L = (13.3 x 10^-6) in/in °F x 3.7795” x 32°F = 0.0016” ∆L = 0.0016” (0.041mm) So the 3.7795 inch cylinder has now grown to 3.7811 inches (96.041mm) . In conclusion if you work in environments that are at one extreme or another on the temperature spectrum you are guaranteed inaccurate measurements. The scenario where measurements are precise but not accurate would be a good illustration for how temperature affects measuring. 3. User Error Lastly, the person doing the measuring also has an effect on the precision of the measurement. Another example is the most effective way to illustrate my point. Consider a situation where an inexperienced measurer measures a part five times and returns five different measurements. Next, a seasoned measurer measures the same part five times and returns the exact same measurement all five times. Both people measuring used the same measurement tool and carried out the measurements at the same temperature. The only variable that wasn’t the same was the person doing the measuring. This variation of measurement between people measuring isn’t that uncommon and happens all the time. Even two different seasoned professionals who inspect and measure parts daily can end up with different measurements for the same part. It is very likely that the variations in the professionals’ measurements will be much more precise when compared to one another. How do I know my Measurements are Accurate and Precise? Alright we’re starting to get into the more interesting - I mean practical, aspects of measuring. Hopefully the last few sections haven’t bored you or deterred you from wanting to measure your own engine components. I assure you, with practice and patience you can become a well versed measuring machine! I want to touch on some practical ways to determine if measurement tools are working correctly. If you went out and bought a cheap or expensive set of micrometers with measurement capabilities ranging from 0-6” how would you know they are accurate right out of the box? Is the manufacturer responsible for insuring they are accurate? Do they ever lose accuracy? Does the fact they were either cheap or expensive matter? The answer to all these questions is that prior to use, regardless of price or quality, most measurement tools will require calibration. Calibration is the practice of checking or setting the accuracy of a measurement tool to a known value. For measurement tools such as calipers and 0-1” micrometers simply ensuring the tips of the tool are clean, closing them together, and making sure the tool reads zero may be all that is necessary. This is a fairly easy method of calibration for these two tools, but isn’t possible for measurement tools where the tips don’t close together all the way (ex. 2-3” micrometer) or the tool has tips that extend outwards (ex. dial bore gauge). For these situations measurement gages are necessary for accurate calibration. Calibration gages (sometimes called standards) come in several varieties depending on tool application. The most common and applicable to engine inspection are gage blocks and ring setting gages. Gage blocks are small blocks of steel (more expensive variants come in other materials) which have been finished to extremely tight tolerances. Gage blocks are toleranced into several different classes. For engine inspection the most accurate measurements that must be made are to 0.0001”(0.025mm). In the measuring world the rule of thumb for calibrating tools is to use a standard which is at the minimum four times as accurate as the tool. So for a micrometer which is accurate to 0.0001” a gage block with an accuracy of at least +/- 0.000025” should be used. What the measuring world does and what the at home engine builder can do feasibly are two different things. For the majority of us our measuring abilities will get in the way of our accuracy long before the gage block used to calibrate the tool has any effect. For this reason I would suggest that using the standards which come with the tools will be fine and not splitting hairs over not knowing the exact accuracy of the standards. If you are shopping for a 0-6” set of micrometers most decent sets will come with standards blocks. The standards will usually come in 1, 2, 3, 4, and 5 inch sizes so all the micrometers can be calibrated at any time. Ring setting gages are similar to gage blocks and are also used for calibrating measurement tools. They are, as the name suggests, rings that have been machined to very fine tolerances. Usually instead of having a tolerance range that the ring falls into the ring will be stamped with the exact diameter it was machined to. A measurement tool such as a dial bore gauge is then calibrated to the exact diameter of the ring setting gauge. Ring setting gages are generally quite expensive as they are challenging to make accurately. Okay, I Understand the Importance of Calibrating My Measurement Tools. What About Making Precise and Repeatable Measurements? Precision gets complicated pretty quick because you have to factor in the measurement tool, temperature, and user taking the measurements. These three variables are difficult to separate completely. However, out of the three variables the user is usually the most likely variable to have a large influence on the precision of the measurement tool. In order to make precise and repeatable measurements it is important to do as many things the same as possible. Here are some things I recommend doing to make sure your measurements are as precise as possible. 1. Make sure the temperature in the room you are measuring is at 68°F (20°C). 2. Try to perform measurements of a part or set of mating parts in a short time period. There’s no need to rush the measurements or to measure all the parts in one day. It’s not that critical but, for example don’t measure the diameter of the piston one day and then wait to measure the bore of the cylinder. That doesn’t make sense. 3. When using micrometers use a micrometer stand to secure the micrometer in place. Not only will this make positioning the part easier and the micrometer easier to read it will also keep the heat of your hands from warming the micrometer. Remember thermal expansion? Believe it or not there are actually studies out there detailing how body heat makes a micrometer expand in length. It’s a minuscule amount but nonetheless worth mentioning. 4. A lot of measurement tools are operated by feel. When working with these tools try to be as consistent as possible when turning the handles. The amount of pressure you apply can have a big effect on the final measurement. For example, the difference between a part that drags hard through the tips of the tool versus one that drags but is soft in feel could be several ten thousandths of an inch. 5. Use your fingertips and a light grip. The fingertips are one of the most sensitive parts of the human body. As such they can be utilized to feel subtle variations in measurement. 6. Instead of just taking one measurement take 3-5. This is something you should definitely do when calibrating your measurement tools. By taking multiple measurements you’ll quickly get a feel for how precise your measuring is. If you are all over the board there is a good chance your technique is inconsistent. If you are within a ten thousandth or two each time you are on to something. For important measurements like cylinder bore diameter, taper, and out of roundness take 3-5 measurements. Then take the average of these measurements and use the average as your final measurement. 7. If you are struggling to determine if your measurement tools are working properly compare them to another known good set. If the two sets are not reading close to identical there is probably a problem with the unknown set. 8. Compare your results to those of someone with a lot of measuring experience. If a seasoned machinist can get your measurement tool to repeat to a ten thousandth of an inch it is probably not the tool. If you have the opportunity to get help from a machinist or someone fluent with measuring watch them carefully. Ask them questions, study how they work the tools, and learn from them. 9. Be patient and take your time. Rushing the measurement process is not a good idea and can lead to silly mistakes. You need to be in a state of mind where you don’t feel rushed and don’t mind taking the time to do a thorough job. 10. Write your results down! Write down everything clearly from the calibration measurements, any calculated averages, and measurements of specific parts. By writing things down you can easily work backwards to see if a mistake has been made somewhere. By keeping in mind accuracy, precision, and resolution you are well on your way to precision measuring like a pro. As I stated earlier, this takes a hefty amount of practice and patience. In my next post Precision Measuring For The At-Home Mechanic // Part Two, I will be discussing in complete detail how to properly use specific measuring tools. There is a definite finesse to using each of these tools as you rebuild your engine, and as you just learned in this post there are many factors that contribute to a precise measurement. Part Two will be posted to the DIY Moto Fix Website next week and you can have it sent right to your email inbox by subscribing to my eNewsletter by clicking below. Subscribe To The Moto Fix eNewsletter Thanks for reading and happy wrenching! -Paul Olesen Moto Mind - Empowering and Educating Riders from Garage to Trail www.DIYMotoFix.com

Paul Olesen

Paul Olesen

 

Piston Ring End Gap and Why You Should Care

I hope all of you in the Thumper Talk community are doing well and have benefited from my last blog post. This week I want to hit on a topic that ties in closely with last week’s topic on warming up the engine and the concept of thermal expansion. Piston Ring End Gap and Why it Matters Let’s talk piston rings. The rings’ primary function is to seal the combustion chamber and keep the pressure that builds on the compression stroke from escaping. Secondly, the rings provide a means for heat to transfer from the piston to the cylinder wall and then to the cooling system. Lastly, on four-stroke engines the rings act as a seal between the combustion chamber and the engine oil. Often times a special oil control ring is used to perform this function and is located furthest from the piston crown. Most of you are probably familiar with the practice of checking piston ring end gap when assembling an engine. What I want to share with you is why it is important to check ring end gap. Checking ring end gap when putting a new engine together or rebuilding an old one is critical because it will determine whether your engine runs flawlessly for countless hours or if you just wasted a whole bunch of money on a bunch of parts that are about to become scrap the first time you run the engine hard. Let me share a quick story with you. The first time I assembled my Kawasaki H2 two-stroke triple engine I couldn’t wait to hear it run. It was tempting to skip all the steps I would call critical to the success of a good engine build, but I’m sure glad I didn’t. First, I noticed that my gearbox was improperly shimmed by the company that back cut my gears. Next, I found that the right hand piston came with the wrong rings! I tried assembling the rings onto the piston and noticed that the gap was almost four times as much as the spec’d value given by the piston and ring manufacturer. Had I decided to run with the rings that had that excessive end gap it probably would not have resulted in a failure. The right cylinder simply would have been down on power since most of the gas being compressed could escape and the cylinder would have low compression. Now what if the situation was opposite what I just described? What if the rings had no end gap? Well, the outcome would have been much worse. Running your engine with too little end gap is a recipe for disaster. It’s time to revisit what I said last week about thermal expansion and how parts expand at different rates. If at room temperature there was no gap between the ends of the piston rings, what would happen when the rings’ temperature was elevated to 180°C? The ring would have no room to expand as it heated up and it would get tight to the cylinder bore, start to want to stick, scuff the cylinder bore, and wreak havoc on your entire engine! This example and explanation is the reason it is so critical to check end gap of the piston rings when assembling a new engine. My advice when setting end gap would be to follow the manufacturer’s recommendations for end gap for their given product. The only time it might be necessary to deviate from their recommendations would be for race applications where more heat is generated than in a normal application. When in doubt, more end gap is always better than too little. Most of you are aware that there are at least two sealing rings in a piston assembly and by now perhaps some of you are wondering if the end gap of each ring should be set the same. In my opinion it is best to set the second ring end gap to be slightly more than the first. The reason for this is to limit the possibility of pressure building up under the top ring. If pressure builds up under the top ring it increases the chance of the top ring fluttering which should be avoided at all costs. By having the second ring’s gap a little looser than the first, any combustion pressure that gets between the two rings has an easier time exiting. For those of you who don’t mind a little math, here is a nice example. How exactly do the manufacturer’s determine the end gap that should be run? Let’s say the rule of thumb might be 0.003” of end gap per inch of cylinder bore for a particular application. Well who the heck decided on 0.003” per inch of bore and why? Let’s assume the following for the sake of simplicity: Cylinder crown temp = 300°C Piston ring temp = 180°C Cylinder liner temp = 100°C The formula for linear expansion is: ∆L = α x D x ∆T where: ∆L = Change in length of the piston ring α = coefficient of thermal expansion (in this case steel = 0.000012m/m°C) D = original diameter of the cylinder ∆T = Change in temperature α = 0.000012m/m°C D = Let’s assume the diameter to be equal to 1”. ∆T = 180°C - 100°C (difference between the liner and ring) Now it all gets put into the equation and solved. ∆L = 0.000012m/m°C x 1 x 80°C ∆L = 0.003015 inches So in our example, using temperatures fairly close to actual engine temperatures, we see that the ring will expand roughly 0.003 of an inch per 1 inch of cylinder bore. Hopefully this gives you a better idea of why the manufacturers specify the end gaps that they do. Moto Mind - Empowering and Educating Riders from Garage to Trail If you'd like to follow my blog, click the "follow this blog" button in the upper right. I'd love to have you.

Paul Olesen

Paul Olesen

 

Now It's Your Turn

How am I doing and what’s on your mind? We are a few posts in I’d like to take a moment to ensure that the most important part of Moto Mind is being taken care of. That part would be you, the reader. Me filling up this blog with content that none of you need or care about would put me on the fast track to having my own online diary! I don’t need a diary for my mental health, I have plenty of fast motorcycles to ride to keep me sane. What I do want is to create a dialogue between you, my readers, and myself so that I can better serve your needs and interests when it comes to your bikes. Over the past four posts I’ve hit on a few topics I feel should benefit all of you. Have you gotten a chance to think about or use them? Any thoughts or tips on your end concerning warming up your engine and piston ring end gap? You guys are the most important part of this dialogue and hearing from you is the ticket to making my time here on Thumper Talk worthwhile. Along with working in some of the content you want to see, I also want to share some of the topics I’m getting pumped to post about. On the technical side, I am going to post an in-depth look at engine balance, continue to post on successful engine building practices, and discuss the importance of keeping a log of the maintenance you perform on your engine. In addition to the technical content I am also planning on taking you through the complete design of a single cylinder two-stroke engine. As I design I am going to explain the process, creating an open door policy on how an engine is designed and why. The two-stroke engine is one of my passions and I would like to see a resurgence of it as a viable powertrain platform for sport vehicles. My aim is to teach you how the two-stroke can be produced using a more clean and efficient design. I hope you’re excited as I am about these upcoming topics. My aim is that this knowledge can serve you as much as it has served me. Give me a holler through the comments below and fill me in on what you want to see more of and what you want to learn about. Moto Mind is merely the sum of its readers and riders. Moto Mind - Empowering and Educating Riders from Garage to Trail If you'd like to follow my blog, click the "follow this blog" button in the upper right. I'd love to have you.

Paul Olesen

Paul Olesen

×