Let's go back a bit and look at the history books shall we. David Vuillemin and Stephen Roncada in 2002 having a nasty battle on track including some aggressive and dirty block passes, leading up to Stephen accelerating up to David's bike, and slamming into his back tire only to have David immediately retaliate by open handed smacking Roncada on his helmet with zero repercussions.
On the very first lap of the season opener in 2004 the world witnessed a beautiful block pass by Kevin Windham on David Vuillemin, sending Vuillemin flying into the tuff blocks later resulting in Kevin being deducted 10 points from his standings which may have cost him the Championship, as we later go on to see that Chad Reed won that year.
Just because they have smaller cc's doesn't mean they have smaller balls, and we witnessed that as 125cc riders Ryan Mills and Steve Mertons (also in 04' season) literally turned a corner of the Supercross track into an MMA octagon ring as they punched and even body slammed each other before race officials had to separate the two spartans. Not to be outdone, the 250 class also drew blood as Brad Langton went after privateer Jimmy Wilson post race showing him that he took his after school Taekwondo classes very seriously as a kid.
The list can go on and on, but where is the line drawn in the sand? Why were these guys not punished? Why was Kevin Windham deducted 10 points for a 'deliberate and vengeful' block pass that mentioned before, could have ultimately cost him the championship that year? Okay fine, times were different back then and times have certainly changed. But have they? Let us take a look at how the AMA dealt with the Dylan Ferrandis on Christian Craig incident this year at Anaheim two. Was this incidental? or was this intentional and vengeful riding leading to an adverse result as stated in the rules and regulations? Or was this just good old fashioned "I want to win" racing? There are many factors to consider when one is racing through a track at a pace so fast that my own grandmother has trouble understanding what is happening on the TV screen, and although we must first protect the riders you can't squeeze the orange without getting some pulp in your cup. In other words, you can't take the racing out of racing. I would very much understand if Christian Craig was seriously injured after making contact with Ferrandis he picks his bike right up and starts riding again. If the AMA has to issue a 12-month probation period on Dylan Ferrandis for making a pass to win the race, mark my words this sport will soon turn into a no contact badminton match in our near future. Heck, that might be even more interesting to watch, instead of a bunch of riders tip toeing around a track, careful not touch ones sponsors stickers on the side of their bikes.
Not all radiator hoses are created equally. This is never more apparent than when your bike’s hose tears, cracks, leaks or collapses. Odds are, your bike is equipped with old-fashioned OEM rubber hoses, which do a menial job.
Chances are, your bike still has OEM rubber hoses, which can crack, tear, and deteriorate. Reliable hoses are a key component in protecting your engine against the dangers of overheating.
Fortunately, advancements have been made in radiator hose technology. Silicone is the new go-to material for hose construction. CV4 has taken it a step farther by utilizing the highest-grade silicone material available. Not only does it improve heat and abrasion resistance, but it also makes assembly and disassembly much easier. When you’re dealing with coolant temperatures around 300 degrees Fahrenheit and extreme pressures, it’s peace of mind knowing that the radiator hoses will hold up.
CV4 radiator hoses are made of the highest-grade silicone, providing consistent performance and protection through countless pressure and temperature cycles.
CV4 is available directly from Wiseco. Want to find radiator hoses for your machine? Call Wiseco today at 1-800-321-1364
Over 2,000 years ago, Greek mathematician Archimedes stated, “The shortest distance between two points is a straight line.” He wasn’t talking about radiator hoses, but the rule still applies. CV4 offers their hose kits in standard and Y-kit configurations. The latter has joints formed into the hoses, which reduces the number of fittings and clamps necessary. Less turns and twists for the coolant to navigate results in improved coolant flow and efficiency. Not only that, the ‘Y’ design helps protect against leaks. Note that the Y-style hose kit costs slightly more than the standard design.
Y-kits from CV4 have joints and intersections molded into them where OEM designs would normally have metal joints and hose clamps. This helps reduce chances of clamp failure and coolant leakage while improving coolant flow.
Don’t wait until your radiator hoses start leaking or collapsing. Father Time always wins, and your OEM radiator hoses are not exempt. It’s important to also understand that when one hose gives up the ghost, the others aren’t far behind. Improve the performance of your bike with a CV4 silicone radiator hose kit. While you’re at it, pick up a new pack of CV4 radiator hose clamps. They are specifically designed for radiator hoses, clamping the hose efficiently without digging into and tearing the hose material like some standard clamps.
See the CV4 products overview on Wiseco's site here.
Many OE style clamps will tear into hoses and compromise their integrity. CV4 hose clamps are designed specifically for radiator hoses and allow for repeated assembly and removal without causing damage.
High Pressure Radiator Caps
Most riders don’t understand the importance of a radiator cap. They remove it every so often to check the coolant level before riding, but otherwise don’t give it much thought. From a design standpoint, a radiator cap is a thing of beauty. Under the cap is a coil spring located between two rubber seals. You don’t have to be Bill Nye “The Science Guy” to understand that water, or coolant, expands as it heats up. That creates pressure inside the radiator. The radiator cap’s job is to keep coolant in the radiator and flowing throughout the cooling system. If there’s too much pressure, the fluid will force the coil spring into the cap. When that happens, incredibly hot coolant will find its way out the overflow hole between the rubber seals and end up on the ground.
When the pressure rating for a radiator cap is exceeded, coolant will flow out of the overflow, lowering pressure and coolant boiling point. CV4 caps aim to avoid this.
While this is designed to protect cooling system components from excess pressure, lower pressure in the system also means a lower boiling point. The key is to find the happy medium between pressure and boiling point. The CV4 radiator caps are equipped with a stiffer spring rated to withstand a higher pressure (but not high enough to cause damage), meaning the boiling point of the coolant in your cooling system will be higher. A higher boiling point is key for efficient cooling, as boiling coolant is not effective in reducing operating temperatures. With a CV4 high pressure radiator cap, the coolant stays where it’s supposed to–in the bike. This is inexpensive insurance for your cooling system.
A radiator cap rated to withstand higher pressure helps protect your coolant from boiling and allows the cooling system to continue efficiently managing the temperature of your engine through a wide range of conditions.
Thermal Barrier Film
Not all performance can be seen. Case in point, many of the world’s top race teams rely on thermal barrier film to keep their fuel cool. Typically applied to the underside of the fuel tank, as well as around the fuel lines, the film resists heat that is given off from the engine.
Sometimes problems out of sight can do the most damage. CV4 thermal barrier film is commonly applied to fuel tanks and fuel line to prevent fuel boil.
Maintaining cool fuel temperature is especially important during the hot summer months and/or when riding at higher elevations when the boiling point decreases. Either factor will cause your bike’s fuel to lose its combustibility, which has detrimental effects on engine performance.
Fortunately, CV4 literally has your bike covered. Choose between two heat resistance ratings. The silver film protects against highly elevated temperatures that reach up to 1200 degrees Fahrenheit. The gold film protects against temperatures up to 800 degrees Fahrenheit, with the added benefit of reducing temperatures by up to 36 percent. Simply cut out the film in whatever desired pattern you choose and stick it wherever heat is a problem.
CV4 thermal barrier film is offered at two levels. Silver protects against up to 1200°F and gold protects against up to 800°F, achieving up to a 36% temperature reduction.
It would be nice if your bike could verbally communicate with you when it’s having a mechanical issue. Fortunately, there are ways to diagnose the problem. Performance changes, weird sounds, odd smells, steam and blue smoke are indicators that something is amiss. Before ever getting to that point, it’s smart to monitor heat emitted by the engine, radiators, shock body, and other vital areas. CV4 adhesive-back temperature strips are the solution.
CV4 thermostrips can monitor temperature just about anywhere you can stick them. Here, Geico Honda uses one on the left-side radiator of each of their race bikes.
Available in a three pack, they are designed with incremental temperature monitoring sections that change color once that temperature is reached. Each strip shows a temperature reading from 149 degrees to 248 degrees Fahrenheit. Installation is easy. Thoroughly clean the desired mounting surface, peel the adhesive backing off, and stick wherever desired. You’ll get an accurate reading every time.
Stick 'em on and the color will change when that temperature is reached. Simple and cheap protection for your expensive machine!
Universal Vent Line Kits
Chemicals, fuel, time and environmental factors are the chief culprits for vent line destruction. For these reasons you may notice that the vent lines on your carburetor, gas cap, radiator overflow, and/or water bypass lines crack or break. Vent lines are important for proper operation, which is why these oft overlooked items shouldn’t be ignored.
CV4 saves the day with their universal vent line kit, which fits a wide range of different model bikes. Made from pure silicone and available in a plethora of popular colors, the line kits are highly flexible for easy installation and removal. What’s most impressive is how the vent line kits are rated to withstand temperatures up to 420 degrees Fahrenheit. That’s a lot of heat! Please note that the vent kits are not designed to replace fuel supply lines.
Simple things like vent line can be overlooked after extended periods of time and end up hardening and cracking, causing annoying issues. CV4 vent line helps keep the simple stuff handled, plus, makes it look good.
Working alongside its factory race teams, Renthal developed the Fatbar36 concept to improve performance through weight reduction without compromising existing handlebar strength. Every time you accelerate, brake, corner, jump, you work against the weight of the motorcycle. By reducing weight, it improves the performance of your motorcycle in all these areas resulting in faster lap times.
Renthal employed its 50+ years of experience in handlebar design, testing, and racing to develop the R-Works Fatbar36 into the ultimate in lightweight motocross handlebars. Utilizing Renthal’s 36Tech™ handlebar standard and proprietary Zarilium™ material to give a high strength handlebar at the lowest possible weight. The R-Works Fatbar®36 is 36% lighter than its standard 28mm diameter Fatbar®, previously the lightest motocross handlebar.
Lightest Motocross Handlebar
At Renthal, they have always strived to produce the strongest, highest quality product they can. Renthal’s current handlebar range is at a strength level its factory level teams feel it needs to be, but weight saving will always be high on their priority list. Renthal made this its priority as well in developing Fatbar36.
36TECH™ – Advanced Technology
36TECH™ is a new handlebar standard developed by Renthal to push forward the boundaries of handlebar technology. The 36mm clamping diameter tapers down to a conventional 22mm control section at each end, using advanced wall geometry, maximizing material efficiencies in wall thickness along the entire length of the handlebar to reduce weight.
New Material – 20% Stronger
Zarilium® is a new aluminium alloy exclusive to Renthal. This new alloy has 20% greater ultimate tensile strength while maintaining the same elongation properties. This additional strength has allowed Renthal to achieve the maximum weight reduction possible while matching the best in class strength of the Renthal® 28mm diameter Fatbar®.
Renthal is at the forefront of handlebar testing. They are the only handlebar manufacturer using data acquisition and equipped with its own in-house test facility. This perfectly positions Renthal to maximize its 50+ years of handlebar design, development, and championship-winning race experience. The result is the best performing handlebars with unrivalled quality.
As the global leader in handlebar technology, Renthal takes pride in not only its engineering abilities but also its state-of-the-art manufacturing facility. Taking raw Zarilium tube, Renthal puts it through a host of operations to turn it into Fatbar36.
The R-Works® badge represents uncompromising performance. It means Renthal has selected the ultimate materials and manufacturing processes at its disposal to bring you the very best performance product they can.
What do you think about the Renthal R-Works handlebar? Is this something only the fastest racers will benefit from? Will you be plunking down your hard-earned cash on a pair? Hit us up in the comments section below and let us know what you think. 👍👎🤐
Making your bike spark arrested just got easier & more affordable.
Manufactured in Canada, Fisch Moto precision machines the spark arrestor body from corrosion resistant 304 stainless steel and it’s held securely in place with 3 stainless steel set screws. Using the included Allen wrench, the Fisch Moto spark arrestor can be installed or removed in a matter of a few minutes.
Spark Arrestor Kit Sizes
Kit 20 (20.0mm-25.4mm / 0.800”-1.000”) Kit 25 (25.5mm-29.4mm / 1.004”-1.157”) Kit 30 (29.5mm-35.4mm / 1.161”-1.394”) Kit 35 (35.5mm-40.4mm / 1.398”-1.591”) Kit 40 (40.5mm-45.7mm / 1.596”-1.800”)
2 or 4 stroke, if your muffler core is round, chances are Fisch Moto has you covered.
From the Horse's Mouth
“There really was no middle ground option on the market for spark arrestors. You could change your full exhaust for one with a sparky in it, or you could dismantle your existing setup and put in something cheap. We just wanted to take our bikes out and ride and there was nothing available that made it quick and easy. We couldn't find a solution so we made one. Inexpensive, and quick to install. No need to set aside an afternoon to clean it out, you can do that in minutes before loading up.”
Henry Pankratz, Co-owner Fisch Moto
Fisch Moto modular spark arrestors are intelligently designed and built to last.
For more information, including an installation video and to purchase yours, checkout the Fisch Moto website.
ThumperTalk Deal: The first 10 to order get 15% off with coupon code TTtop10
1) Clean it –
a) Like you have never cleaned it before. Power wash. Foaming engine bright. Toothbrush – use your old one and toss it when done. (Your wife may divorce you if you use hers or yours and put it back in the bathroom.)
b) Get all the crap out of the nooks and crannies. Make it shine!
c) Pull out the steel wool and clean the aluminum rims, swing arms, etc.
d) Remove all stickers, numbers, etc. Clean up so you cannot tell they were there. No one cares about your numbers and they make me think you raced the crap out of it. If they are custom numbers – maybe leave. Probably not if 3 digits = hard core racer. 1 or 2 digits = garage racer.
e) Use STP Son of a Gun or Armor All to make the plastics and tires glow.
f) Lube it up – chain, footpegs, kick starter.
2) Fix anything that you can – broken plastics or other parts.
a) If the cases are worn, consider the plastic covers to make it look good.
b) Frame guards are cheap and make it look new.
c) Use fine sandpaper to clean up the plastics.
d) Try to lube or clean off any rust.
e) Paint is cheap….
3) Pictures – Do’s after cleaning in a well-lit area, with flash.
a) Close up of bike only- left and right side.
b) Front left and front right.
c) Front and rear tires to show treads. If you can see the ‘vent spews’ or gates let them see it.
d) Show close up of sprockets to show wear
e) Close up of the engine on both sides.
f) Rear of the bike.
g) Hour meter if you have one
h) Any damaged area – dent in pipe, big scratch. Full disclosure.
i) Manuel – if you have it. If not find it online and print one – and put it in a nice binder with a cover page.
j) Picture of included stuff – nicely arranged, organized, etc.
k) Title – maybe cover up part of the numbers to prevent scammers, etc.
l) Picture of the model plate –One guy thought he was selling a different year.
m) VIN – to share later via PM or text and give them the location to check not stolen. https://www.vehiclehistory.com/
4) Pictures – Do not …
a) Show pictures of the bike through the ages. When new from 10 years ago. Or even before last plastics or stickers change. I am never sure what bike I am buying.
b) Show pictures of the bike in your truck or dirty or anywhere but just before you list and just after cleaning.
c) Show anything else but the above.
d) Show pictures of you jumping or wheeling or anything. One idiot had a picture of him flying 15 ft through the air and you could barely confirm it was the bike. I don’t want to see you or the bike jumping. I’m not buying that, I am buying the bike.
e) Show a picture of the bike when stored outside next to your pile of crap
5) Listing Description –
a) Give them details about the bike – estimated hours on each of the old and new perishable parts
b) Tell them what is great
c) Tell them what needs work
d) Tell them what is broke
e) Tell them the kind of riding you do and have done. Be honest. If you have raced every weekend there are pictures and listing out there.
f) Tell them how it starts – cold and hot. 4 kicks cold and 1 hot.
g) Tell them what might need to be done in the future.
h) Details – some people need them.
i) Give them the nearest cross streets without giving address in the listing. Give that when they are on their way.
j) See #8 on price.
6) Prepping for the Visit
a) I always start the bike regularly while in the sale mode (weekly). I would rather have an issue in advance. I once was selling a YZ 85 and my kids left the gas on. Plug got fouled and I ended up giving the guy $200 off because it would not start. I had a spare plug, that was also fouled. He got a new plug on the way home and it fired right up.
b) Tell kids the bike is off limits – see #1.
c) Start the bike before the buyer gets, there unless they ask for it to be cold. Even if they want it cold, it would be cold 1 hour after you started it.
d) Try to make the garage look like a showroom. I don't want to climb over your crap or be covered in grease. I don't want you dogs sniffing my crotch or scratching my truck.
e) Have a plan about them riding the bike – Helmet? Hold their keys and license so you don’t get scammed.
f) Be Prepared – Have a spare set of tie-downs, so when they break out the ratchets ones you can save the day. Tools to remove handlebars if they try to shove in SUV.
7) Negotiation –
a) Have the price pretty well nailed before they come.
b) Be Prepared to lower the agreed-upon price if they find something you did not disclose. I had a guy find a hairline crack in the rims once. So I had to lower the price a little more than I wanted.
c) A good deal is when both walk away happy.
d) Don't be afraid of silence on the phone or text when you make a counteroffer.
e) Know that you are not going to get your money out of the extra $2000 you put into the bike in rims, hubs, and pipe. Sorry. Pull them put the stock back on and sell separately.
f) Give an address near you until they are just about to leave.
😎 Research – (Buying or Selling) – do your homework before you list. Know what a reasonable price is for the bike. You don’t want to look like an idiot by listing too high or leave money on the table.
a) Look at other similar bikes use the good from their Ads and remove the bad.
b) Calculate in your proximity to other buyers. If you live way out, you are going to get less.
c) Do your homework on the buyer before you give them the final address.
d) If on Facebook, look at their profile. Know your buyer. Don't get scammed.
What did I miss?
At Wiseco, we’ve been manufacturing top-end two-stroke engine components for decades and have been building engines for just as long. To ensure your Wiseco top-end parts run trouble free, we’ve put together some top-end rebuild tips that will ensure your next build is your best build. These tips will be discussed chronologically and will encompass all phases of the build from diagnosis and preparation, to disassembly, through post build. The tips we’re going to share shouldn’t be considered inclusive of everything that has to be done but are tips that focus on things that are either often overlooked or incredibly important. Let’s dive in!
Pre-teardown activities can be an insightful way to help pinpoint any internal issues and prepare for upcoming work. Check out these three pre-teardown tasks that will streamline the whole process.
Diagnosis - Before tearing the engine apart, are there any signs that a specific problem exists? If so, are there any diagnostic tests such as compression or crankcase leak down that are worth performing? Service Manual - Performing engine maintenance without an OEM factory service manual is not recommended. Make sure you have a manual for your machine prior to starting work. The manual is the only place you’ll find service limits, torque specs, and other key data. Clean Machine - Take the time to thoroughly clean the machine before opening up the engine, especially if you will be servicing the top-end without removing the engine from the machine. Need some tips on knowing when to replace your piston? We have a guide here.
It doesn't have to be spotless, but cleaning off excessive dirt and mud can make it a lot easier to keep debris out of citical components during your rebuild.
Perform disassembly steps methodically and be cognizant of the fact that the bottom end of the engine will be exposed to the elements. Take every precaution to ensure dirt, debris, and hardware does not get into the bottom end. Bearings and other running surfaces have an incredibly low tolerance for dirt, no matter how little.
Protect the bottom end - Once the cylinder has been removed, wrap a clean, lint-free rag around the top of the crankcase.
Keep your bottom end components protected with a clean rag covering the exposed crankshaft opening.
Piston removal - Easy piston circlip removal can be accomplished by using a pick and needle nose pliers. Insert the pick into the dimple in the piston and behind the circlip, then use it as a lever and pry the circlip part way out. Once part way out, grab the circlip with needle nose pliers. During this process, be careful not to scratch or mar the wrist pin bore, as this will make removing the wrist pin much more difficult.
The ease of pin removal will be largely dependent on the engine design and condition of the bore. If the pin can be removed by hand, great, if not, light tapping while supporting the rod is permissible. Otherwise, a pin puller should be utilized, which can be bought or made. In its simplest form, this can consist of an appropriately sized bolt, nut, and socket. Once the wrist pin has been removed, the piston can be removed from the rod.
Removal of your old piston should be carefully handled. Cautiously remove the circlip and the wrist pin to get the piston off the connecting rod. Carelessness during this step could damage your connecting rod or crank.
Power Valve Disassembly - Prior to taking the power valve system apart, spend some time reviewing the procedure in your service manual. For additional insight into how the components interact, review the exploded views in the service manual and look at part microfiches which can be found online.
When removing the power valve system, consider laying the components out on a clean sheet of paper in an orientation that correlates to how they are installed in the engine. This is a relatively simple thing to do that will help you remember how they are installed later. When it comes to cleaning the components, clean them one at a time or in small batches so that they don’t get mixed up.
Take note of how your powervalve is assembled and operates before taking the components off for cleaning.
Meticulously check all the top-end parts to ensure they are in good working condition. Rotate the crankshaft by hand and feel for smoothness in the crank and rod bearings. Review the items below for often overlooked inspection opportunities.
While the top end is apart, inspect your connecting rod and crankshaft to ensure everything is in good operating order.
Reed Valve - Don’t forget to check the condition of the reed valve petals, cage, and any stopper plates. Most service manuals will detail the acceptable clearance between the petal tips and cage as well as the stopper plate height. Ensure any rubber coatings on the reed cage are in good condition. Intake Manifold - Check the intake manifold for cracks. Cracks are more common on older engines, and if they propagate all the way through the manifold, can lead to air leaks. Exhaust Flange - Check the condition of the exhaust flange and ensure that it is not excessively worn. An excessively worn flange will make exhaust gas sealing difficult, hamper performance, and leak the infamous spooge. Power Valve Components - Take a moment to review the condition of all the power valve components. Significant wear can occur over time and lead to performance losses. Rod Small End - Check the small end rod bore for surface defects such as pitting, scratches, and marring. Any severe defects in the bore will necessitate rod replacement. New Parts
Once you’ve disassembled the engine and have a full picture of any issues, make a list of everything you’ll need to replace. At the very least, you’ll likely be replacing the piston and top-end gaskets. Forged piston kits are available from Wiseco for a wide range of applications, and include the piston, ring(s), wrist pin, and circlips. Many applications can also be purchased with a complete top-end gasket kit from Wiseco. Wiseco pistons are available with features and pricing ranging from reliable replacement to race-focused.
Replace your top end with quality components. Shown is Wiseco's Racer Elite two-stroke piston kit. Check out everything Wiseco offers for your machine here.
Trying to decide between single-ring and two-ring? Check out our explanation here.
The number of measurements that should be taken throughout the top-end rebuild will be discretionary. At Wiseco, we strive for excellence and err on the side of caution when it comes to engine building, so our builds consist of numerous measurements and inspections prior to reassembly. For us, this ensures a high level of confidence and safeguards against external oversights. We recommend the same to anyone building an engine.
Below is a list of measurements that we routinely make when rebuilding a two-stroke top-end:
Piston ring end gaps
Checking ring end gap involves inserting the piston ring into the bore and using feeler gauges to determine how large of a gap there is. You should compare your measurement to the spec outlined in your owners manual or piston instructions.
Rings commonly come pre-gapped, but some fine-tuning may be required after measuring. Ring end gaps should be filed evenly, small portions at a time to reach the desired spec.
Piston ring to ring groove clearance This measurement is double-checked by Wiseco during manufacturing, but it never hurts to double-check.
Ring to ring groove clearance should also be checked and compared to the recommended spec in your manual/piston instructions.
Piston to cylinder clearance
Measuring piston to cylinder wall clearance involves measuring the diameter of the piston and subtracting that from the bore diameter. Be sure to follow your piston instructions on measuring your piston at the proper gauge points.
Wrist pin to piston clearance Please note, pin fit is done by Wiseco during manufacturing, but if you have the tools, it's always a good idea to double check.
Making sure your piston has proper clearance involves measuring the wrist pin diameter and subtracting that from the pin bore diameter. This can accomplished using a bore gauge set and a micrometer.
Rod small end diameter Power valve components Out of these measurements, confirming or adjusting the ring end gaps is by far the most important, followed closely by ensuring the cylinder bore is within spec with respect to diameter, straightness, and roundness. Understandably, some measurements may be difficult for the average home builder to execute, usually due to not having the right equipment, however, a competent shop should be able to assist.
Before putting everything back together, take the time to prepare individual components so they aren’t overlooked or forgotten.
Cylinder Cleaning - Once the cylinder has been deglazed or has come back from replating, it should be cleaned one final time. There is almost always leftover honing grit that will need to be removed. To effectively clean the cylinder, use warm soapy water and a bristle brush followed by automatic transmission fluid and a brush or lint-free rag. To check the cleanliness of the cylinder, rub a cotton swab around the bore and look for contaminants. Clean the bore until no contaminants are visible on the cotton swab. Any honing grit that remains in the cylinder will facilitate premature wear of the piston rings.
Cylinder prep is incredibly important for a top end rebuild. Make sure your cylinder's plating is in good condition and it is properly deglazed, honed, and cleaned. Read our complete guide to cylinder prep here.
Does your cylinder need the exhaust bridge relieved? We explain that here.
Power Valve Function - Cylinders that have been exchanged or replated should have the power valve system reinstalled ahead of final installation. Often times, excess plating can inhibit power valve movement. To correct this, the excess plating must be carefully removed. On cylinders utilizing blade style power valves, the blade position with respect to the cylinder bore should be checked to ensure the blade does not protrude into the bore.
Make sure your power valve is reassembled and functioning properly before reinstalling the cylinder.
Piston - It is usually easiest to prepare the new piston as much as possible by installing one of the circlips and the ring pack ahead of joining it to the connecting rod. Unless your service manual dictates which circlip must be installed first, choose the easiest installation orientation. Typically, your dominant hand and preferred work orientation will dictate which side you choose to install the circlip on.
Reference your service manual to determine the correct orientation of the circlip. Usually, the open end of the circlip should be oriented to the 12 or 6 o’clock position. Temporarily install the wrist pin and use it as a backstop so that the circlip is forced to move into its groove. Installing the circlip should be done by hand to limit the chance of deformation. Orient the circlip to the desired position, then push the open ends of the circlip into position first. Be careful not to scratch or mar the wrist pin bore in the process! Once installed, use a pick or screwdriver to confirm the circlip is fully seated and does not rotate. Any circlips that can be rotated must be replaced because they have been compromised and deformed during installation.
It's easiest to install your ring pack and one circlip before installing the piston on the small end of the rod.
Rings - The compression ring(s) will be directional, and the top of the ring is typically denoted by markings near the end gaps. Apply a thin coat of oil to the ring, then carefully work the ring into position.
Ensuring the ring end gaps are lined up with the locating pins is crucial to proper 2-stroke engine operation. Read more about locating pins here.
Carefully work through the installation process by paying attention to the small details. Double check instructions and don’t force anything that feels abnormal. Be especially careful when mating the cylinder to the piston assembly.
Piston - On the top of the piston, an arrow will be imprinted, which typically denotes the exhaust side of the piston. Consult your service manual and/or instructions that came with your piston kit to confirm the proper orientation of the arrow and piston. Apply a light amount of assembly lube to the small end bearing and wrist pin bore on the piston, then install the bearing, align the piston with the small end of the rod, and slide the wrist pin into place. Once again, use the wrist pin as a backstop then install the remaining circlip into position. Use a pick or screwdriver to confirm it is fully seated and does not rotate.
When installing the new piston on the connecting rod, make sure the piston is correctly oriented, usually with the appropriate marking facing the exhaust side. Also, apply lube to the new small end bearing and wrist pin bore.
Cylinder to Piston - In most applications, a ring compressor is not required to compress the rings and install the piston into the cylinder. Lightly oil the cylinder bore with assembly lube or engine oil. Then, lube the piston skirt and ring faces. Prior to installing the piston and rings, confirm one final time that the piston ring ends are oriented correctly to their respective locating pins.
Before sliding the cylinder onto the new piston, apply some lube to the piston skirts, ring faces, and clyinder wall. It's critical to make sure the ring end gaps remain correctly oriented with their locating pins throughout cylinder installation.
Position the piston at or near TDC, then carefully lower the cylinder bore down onto the piston. Use your fingers to compress the ring(s) and ensure the cylinder bore is square to the piston. Feel how easily the cylinder slides over the piston and rings. The installation of the cylinder should be smooth and offer little resistance. If resistance is felt, stop immediately and assess the ring pack. Occasionally, one of the rings may come out of position in its groove and snag the cylinder bore. This typically happens as the ring transitions out of your fingers and into the cylinder bore.
When installed correctly, the new piston should move smoothly up and down in the bore without any snags or notchiness.
Always make sure to torque your cylinder and head bolts to the spec outlined in your owners manual. Tighten the head bolts in a star pattern to prevent warpage.
Before firing up your fresh top-end, do these three things to ensure the engine performs optimally.
Crankcase Leak Down Test - As one final precautionary measure, perform a crankcase leak down test. A crankcase leak down test will help confirm all the seals, gaskets, and joints are sealing as they should.
Spark Plug - Don’t forget to install a new spark plug, and, if necessary, gap it appropriately.
Air Filter - Be sure to install a clean air filter prior to start up.
A crankcase leakdown test can help ensure your new rings are sealing properly before initial fire up.
Ready to break in the engine? Check out our complete motorcycle engine break in guide here.
Top-end rebuilds shouldn’t be taken for granted or oversimplified since they deal with the heart of the engine. With adequate preparation, the right tools, attention to detail, and the appropriate knowledge, top-end rebuilds can be performed by anyone and yield great results. At Wiseco, we’ve performed countless engine builds and hope the information we’ve shared makes your next engine build go smoothly and successfully.
This YZ250 engine is ready to rip like new again with a fresh Wiseco top end!
Clean the entire bike with a mild detergent and water. Avoid directly spraying bearings and seals as to not force water into them. If you use a pressure wash, be VERY careful of this. If possible, start and ride the bike to evaporate any water trapped in the motor and drag your brakes to dry them as much as possible. If not possible, compressed air or even a leaf blower will work in a pinch.
Photo Courtesy of @Hans Schmid
Clean your chain with a bristled brush and mild degreaser such as most household dish soaps. Dawn is a good choice. Liberally spray your clean chain with WD-40 (Water Displacement 40th Attempt) and wipe off the excess with a shop rag. Finish the process with your favorite spray chain lube. If you have an o-ring chain, make sure to use o-ring safe lube.
While you’re still in lube mode, take your WD-40 and spray down the foot peg pivots, kick start pivot, folding shifter pivot and lever pivots. Get out your cable luber and lube your control cables. When doing this, it’s a good time to inspect brake pads, suspension linkage, chain and sprockets and such for wear. If your motorcycle is equipped with grease zerk fittings, go ahead and give them a few squirts of quality grease. Lastly, air up the tires to spec.
If you're going to store in a space that rodents can get in, Install an air box washing cover and silencer plug. Leave a note taped to the handlebars so you remember to remove both before starting in the spring.
There are different methods of winterizing fuel systems, but these are the methods we prefer, having had good luck using them over the years. If your bike has a steel fuel tank, it’s very important to fill it to the brim with fresh fuel. Filling the tank completely will stop it from rusting, which is a major issue in some areas. Plastic fuel tanks are more forgiving, but keeping it full will minimize the formation of condensation.
Fuel stability is another concern, as most fuels begin to breakdown after about 60 days. We prefer to fill the tank with race fuel. In contrast to pump fuels, race fuels can be left for longer periods of time and will not turn to varnish. The alternative is a product called Sta-Bil. Many people use this product with good results and it is a safe bet when race fuel isn’t available. Once the fuel has been stabilized, start the motorcycle and let the fuel circulate throughout the entire system. Another option is to completely drain the fuel tank and carburetor. This can be done with EFI as well, but how-to is beyond the scope of this article.
Not all dirt bikes have a battery, but if you’re lucky enough to own a bike with a magic button, this area concerns you. Lead acid batteries are still prevalent, but light-weight batteries such as Lithium Ion are coming from the factory more and more. It's important to know which you are running as it relates to any sort of voltage maintenance equipement (E.g Battery Tender) you might be using. In the case of Lithium Ion batteries, lead acid chargers may overcharge Lithium batteries and some have Desulfation Modes that can spike voltage. Both can damage a Lithium battery. If your storage is 6 months or less, you likely won't need to charge a properly stored Lithium battery, as their discharge rate is very, very low. If your not sure about your battery's maintenance requirements, check with its manufacturer.
Regardless of the battery type, it's a good idea to pull the battery and store it in a climate controlled space such as a dry basement or closet. Be sure to clean the battery terminals of any corrosion before storing and place tape over the terminals to avoid accidental shorting.
Engine & Cooling System
A fresh oil change should be done before you store your bike. Dirty engine oil contains corrosive contaminants that you don’t want to leave in the engine over the winter. If you’re in a coastal region, a fogging oil should be applied through the spark plug hole also. With the spark plug out, shoot a few sprays down the spark plug hole and turn the motor over a few times while holding the kill start button. Once the fogging oil has been applied, install the fresh spark plug.
If the coolant is do for a change, now is a good time. Be sure that your coolant has sufficient antifreeze properties for your storage conditions. You'll need the right Hydrometer for the coolant type you're checking (Ethlene Glycol vs. Propylene Glycol like Engine Ice).
Besides engine fluids, the brake and hydraulic clutch fluid should be topped off and replaced if there is any doubt. Brake fluid naturally draws moisture (hygroscopic) over time, so changing it before you store you bike each year is a good idea.
If you have the luxury of heated storage, all the better. The less you expose the motorcycle to extreme temperature fluctuations the better. Store the vehicle on a stand. This eliminates any flat spots forming in your tires as well as letting the suspension relax. If a stand isn't an option, put a piece of plywood between the tires and any cold concrete to stop dry rot. If you're not in a coast region or in a dry climate, cover the bike with a tarp or old sheet to keep dust to minimum. They key here is keeping the vehicle clean without trapping moisture. You can put a light coating of WD-40 on any parts that are prone to corrosion, just be sure to keep it away from your brake discs & pads. Another good option is S100 anti-corrosion spray.
When the wonderful sights and smells of spring arrive, it’s time to ride! Since you did all the work when you stored your bike for the winter, spring startup will be a breeze. Install the battery if so equipped, but double check the voltage first. If you stored your bike full of fuel, drain the carb float bowl to allow fresh gas from the tank in. Even though the fuel was stabilized, the small volume that is contained in the float bowl will deteriorate much quicker than the much larger volume in the tank.
Double Check all fluids and you may even consider changing the oil again if it was stored for an inordinate amount of time (a year or longer). Check the air pressure in the tires and your ready to fire it up. If you did your job correctly, the motorcycle should spring to life. Take a extra few minutes at warm up to check for any fluid leaks or strange noises. If all is good, you’re ready to tear it up!
Winter Option B?
Checkout the Snow Bikes Forum on ThumperTalk!
Like most things in life, there is more than one way to do something. This article doesn't mean it's the ONLY way to winterize motorized toys, so if we've missed something or you have a different way of gettin' this done, hit us up in the comments section below. We want to hear from you!
Whether you ride a dirt bike, ATV, or any other powersports machine, the time for a bottom end freshening up will come. Hopefully it doesn’t come because of a crankshaft failure, but we all know sometimes stuff happens. Regardless of the reason you’re rebuilding your bottom end, ordering durable parts and having everything you need makes it a lot easier on your mind and your wallet.
An extensive process of designing, engineering, quality control, and benchmarking goes into every Wiseco bottom end rebuild kit. Wiseco’s bottom end kits consist of the crankshaft itself, a bottom end gasket and seal kit, and main bearings. Each application has one part number for the complete kit, making it simple and easy for the customer.
Finding individual part numbers for all the seals, bearings, and gaskets you need can be a pain. We think receiving everything in one full bottom end kit is much easier.
Research and Development
Wiseco’s engineering staff is responsible for the complete design of all Wiseco crankshafts, including all assembled dimensions, clearances, materials, and specifications. During the research and development process, the engineering team will first examine the OEM crankshaft. They will take numerous measurements of lengths, widths, thicknesses, tolerances, and clearances. OEM crankshafts will be put through this testing process first, allowing engineers to determine where there are weaknesses in those crankshafts so they can tailor their designs to improve upon those areas.
The first step in crankshaft reliability is using properly treated materials.
One critical component of all Wiseco crankshafts is properly treated materials. Crankshaft webs and connecting rods are double forged for strength, and then put through heat treatment. Proper heat treatment on connecting rods and main webs of crankshafts normalizes the materials and is essential to wear resistance because it prepares the metal for the heat and stress conditions experienced during engine operation. Without this process, the rod and crank webs could have inconsistent qualities and weak spots. If the crank components don’t have the lowest friction and best possible wear protection, some or all of the affected crankshaft components could fail, which is almost always catastrophic for the entire engine.
Also included are low friction bearings. Optimally located rod oil slots help keep these low friction bearings properly lubricated. A main bearing that spins smoothly and easily while also operating within strict tolerances is important to allow your engine to perform quietly and efficiently, without any accelerated wear from operation outside of tolerances.
Keeping crank bearings properly lubricated and free of debris is essential to crankshaft function.
Before designs are finalized, crankshafts are installed in a motor and tested at wide open throttle for 4 hours. If a crank or any part of it does not last for the entire 4 hours, the engineers will reexamine and redesign any parts needed. When the crank lasts the full 4 hours, it is next inspected for signs of high wear resistance, so Wiseco can be sure the crankshafts will have many hours of service life.
Testing and Quality Control
The first step in the quality control process for the crankshafts is ensuring consistent quality across every part that comes in. Wiseco has created close relationships with their material and parts suppliers to make sure that each and every part going into their cranks meets strict quality standards.
A great example of the importance of working with suppliers is the big end bearings used in Wiseco crankshaft assemblies. Cleanliness of the bottom end bearings is a major factor in proper crank operation. If there is any debris from manufacturing in a main bearing, wear on the bearing will be accelerated, leading to bearing failure, and ultimately, crank failure. Adequate filtration systems and processes have been put in place with the supplier to make sure debris is taken care of right away. Individual inspection and initial testing steps are also taken by the supplier to assure quality begins at the source.
Quality control steps for cleanliness, material, and operation start at the supplier, and don't end until everything is boxed up and ready to ship.
The next step in the crankshaft assembly after parts are received from suppliers is to thoroughly hand-inspect for any imperfections or dimensions outside of Wiseco’s specifications.
According to Wiseco's Director of Powersports, Scott Highland, “A sample group from each incoming shipment is fully inspected in our engineering lab prior to being placed in inventory to be sold. Inspection is fully dimensional, and all data is recorded and compared to standards for each specific crankshaft.” Crankshaft pieces that pass inspections are then used to assemble the crankshafts themselves, then sent off for further testing.
The assembled cranks are first tested for any operation that runs outside of specified tolerances. This is referred to as testing the crank for trueness. If there are any that are found to not operate completely within the specified tolerances, they will not be used.
Crankshafts are individually measured and inspected to make sure all critical dimensions are met.
Scott Highland comments, “Inspecting crankshaft run-out, or trueness, is critical to the crankshaft running smoothly in the engine with less vibration and improved main bearing wear.” Any part that is not in compliance will be recorded and scrapped.
OEM Following the Aftermarket
Back when Honda was still making the good old 2-strokes, there were certain model years that had what the powersports industry refers to as the “tin can” design for the crankshaft. What this nick name refers to is the web of the crankshaft -- which is the section that houses the main bearing and shaft -- had a surrounding metal piece that resembled somewhat of a tin can. The connecting rod would rotate on the main bearing through the middle of this “tin can.” The natural highly repetitive motion of the crankshaft would cause a great deal of fatigue on the tin can, which ultimately resulted in the metal fracturing and metal fragments falling into the crankshaft.
Wiseco created a newly designed crankshaft for the CR250R models that came with the faulty “tin can.” Their new design scrapped the tin can structure and utilized more conventional plastic stuffers that were much more resistant to wear, drastically reducing the chance of bottom end failure. After endurance testing, it proved to be a worthy design. In fact, the new design worked so much better that Honda later started using a similarly designed crankshaft with plastic stuffers instead of the old faulty design.
It’s always a good idea to inspect the bottom end components of your machine and replace as needed according to your manufacturers suggestions. Ordering one bottom end kit from Wiseco and receiving everything you need at a fair price makes the first steps of your rebuild a whole lot easier.
Beta presents the race-ready version of its new-generation Beta Enduro range, unveiled back in July. As customers have come to expect, it's fitted with all the equipment needed to make it a truly race-ready machine, set up for any situation it'll encounter during competition.
Beta engineers have therefore focused on developing a high-end set-up and incorporating all those details - both aesthetic and functional - that reduce weight and ensure even higher performance under all race conditions.
The new RR Racing MY 2020 has, in fact, all the same features that have enabled Steve Holcombe and Brad Freeman to dominate the World Enduro circuit over the last few years, winning several titles in succession.
The Racing family consists of 7 models: 125, 250, 300 cc 2T (2-stroke) and 350, 390, 430 and 480 cc 4T (4-stroke).
Compared to the respective standard versions, the RR Racing MY 2020 range stands out on account of:
Kayaba AOS forks with closed ø 48 mm cartridge: these new KYB spring forks feature a closed-cartridge design and are renowned worldwide for being top-of-the-range. Close collaboration between Beta and Kayaba has created a bespoke product which features a new fork shoe design and a unique calibration reserved for the RR models. Also, the presence of anodized internal components minimizes sliding friction, whilst the customary compression and release adjusters allow easy attainment of optimum settings at all times. Therefore, Kayaba forks ensure excellent operation under all usage conditions, being ultra-reliable, easy to tune and, what's more, considerably reducing weight (0.5 kg lighter than the MY 2019). ZF ø 46 mm shock absorber with new calibration: this newly refined set-up lets riders make the absolute most of the new chassis. Black anodized triple clamp. Premix
In response to riders who are always looking for slashing weight, the Beta R&D department has once again decided to dispense with the automatic mixer in order to reduce bike weight as much as possible. RR Racing MY 2020 2-stroke machines run on oil/gas premix, thus honing the racing pedigree of this version.
Quick release front wheel pin: essential for saving precious seconds during a race, this device speeds up tire repairs. Vertigo hand guards: solidity, eye-catching design and In-Mold graphics make this accessory indispensable for off-road riding. Metzeler Six Days tires: for confident off-road riding. It's no coincidence that these tires are the most widely used in top-level Enduro competitions and by multiple world champion Steve Holcombe. Black Aluminum footrests: with a broad contact surface and steel pegs to ensure optimum grip under all conditions. A robust yet lightweight structure means these footrests also have a longer lifespan. Rear sprocket with anodized aluminum core and steel teeth: a perfect combination of lightness and durability. Red aluminum chain tensioner blocks. Racing seat with pocket. Black anodized shift/brake levers. Transmission oil cap, engine oil cap and oil filter cap in red anodized aluminum. Racing graphics and red rim stickers. New battery charging system: more efficient and reliable (4-stroke only). New expansion chamber: improves performance across the entire power curve, especially at high revs where it boosts acceleration (125 2-stroke only). Availability
November Want more on Beta Motorcycles? Checkout our Beta Motorcycles owners forum.