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Different machines, types of riding, and skill levels may benefit from different clutch setups. So how do you decide which clutch is right for you? Here, we break down each of Rekluse's clutch offerings to help you make an informed decision. While riding a motorcycle may seem elementary to an experienced individual, it’s not the act of riding that’s so impressive as how a motorcycle works. Very few people take to the time to think about all of the minute steps required for a bike to even start, let alone be ridden. Of course, there’s the piston pumping up and down, fuel igniting in the combustion chamber, and the crankshaft turning energy into rotary motion. One of the most overlooked components of an engine is the clutch system. In fact, it’s generally considered an afterthought; that is, until it stops functioning properly. Never overlook the importance of a properly functioning clutch. Motorcycle enthusiasts may view the engine’s clutch as a small piece of a large puzzle, unnecessary to worry about until new clutch plates are required. However, the clutch can actually be a huge performance advantage. Rekluse, an Idaho-based company that has been making their own line of clutch systems for 17 years, knows this all too well. Their first centrifugal automatic clutch (known as the Z-Start), put them on the map. Top off-road racers across various disciplines have raced, and won, with the Rekluse auto clutch. As an aftermarket company, reaching the pinnacle of the sport can’t be accomplished by offering an inferior product. Every component is tested to its maximum capabilities before ever being used in a race situation. Today's Rekluse clutches are the result of 17 years of development, engineering, and testing. This is an ever-evolving process that fuels Rekluse's continued development. Rekluse offers six different options across the auto and manual clutch categories for dirt bikes. Although known for their automatic clutch systems, Rekluse makes state-of-the-art manual clutch packages. Which one is right for you? Auto or manual? RadiusCX or EXP 3.0? Core Manual TorqDrive or Core Manual? Read on to find out. Understand Your Options Think about your preferences, expertise, and shortcomings as a rider. Are you a beginning motocross racer, focused on mastering throttle control and maintaining corner speed? Perhaps you’re an avid trail seeker, searching for unconquered terrain in the most hostile environments. Whatever the case, it’s important to understand that your bike’s clutch can either help or hinder your goals as a rider. Understand that you have options. Different riders will benefit from different clutch setups. Read on to understand which of the various options will be most beneficial for you. Conventional clutch systems can be easily abused, leading to premature wear and eventual failure. Constantly pulling in and releasing a clutch lever causes fatigue. Automatic clutches can help solve those problems. Is there a drawback to using an auto clutch? Some may find the technology foreign, requiring practice in order to achieve comfort. Wrap your head around the idea of coming to a stop with the bike in gear and your hand off the clutch. Fortunately, Rekluse covers the spectrum of clutch configurations. Rekluse Technology Through extensive research and development, Rekluse created three technological advancements that are shared among various clutch systems in their line. These components are a telling sign of Rekluse’s commitment to achieving clutch mastery. EXP The Houdini of clutch tech, Rekluse’s EXP disk is responsible for engaging and disengaging the clutch based on centrifugal force. When the motorcycle reaches a certain rpm, the EXP wedges slide out to expand the disk and engage the clutch. All of this is happening from engine idle to about 3,000 rpm. The point at which the clutch engages can be fine-tuned with different wedges and springs for a customized feel. The EXP disk is the key to auto clutch performance. This is the piece that automatically expands and contracts based on RPM to engage and disengage the clutch. Austin Paden, Rekluse Product Manager/Race Development, elaborates, “There was a lot of thought that went into the ramp angles during the development process, and how the wedges would ramp out while rotating. Small changes to the wedges made a big difference in how the auto clutch performed. Our goal was to make something lightweight, easy to adjust, and functional.” This graphics illustrates the simple, but innovative, process of the EXP disk and how it achieves auto clutch functionality. EXP technology is utilized on the RadiusCX, RadiusX and Core EXP 3.0 automatic clutch systems. Read more about how EXP works and find clutch systems with EXP here. TorqDrive Exactly what the name implies, TorqDrive is based on the principle that using more friction plates in a clutch pack creates increased torque capacity. Rekluse accomplished this by decreasing the thickness of their plates in order to use more plates in the same confines, while developing their own friction material for increased durability. Check out how TorqDrive increases torque capacity. Paden states, “The idea was to increase torque capacity to the system. Ultimately, the goal was to allow for more tuning options, lighter feel at the lever, and lessen clutch operating temperatures. The world of Supercross and motocross is based around a standard functioning manual clutch. The market in that segment is very competitive. We learned that other companies were using standard-based friction plates. Yet race teams were still having issues with breaking friction plates and experiencing clutch fade, which was caused by expansion. Our goal was to find a fiber compound that was durable, even when the operating temperature became extremely hot, yet be thin enough to fit more fiber plates into that same working area.” "Our goal was to find a fiber compound that was durable, even when the operating temperature became extremely hot, yet be thin enough to fit more fiber plates into that same working area." - Austin Paden, Product Manager The friction plates are made out of steel, which bucks the trend of using aluminum. When subjected to extreme heat, aluminum expands roughly twice as much as steel. Expansion leads to clutch fade. Rekluse essentially solved an age-old clutch malady through metallurgy. Additionally, the steel-based friction plates have unusually shaped friction material totally unlike a traditional square or rectangle-shape. Paden explains, “We came up with our own fiber material and design, which is based around oil flow. That material is on a steel core, which maintains its integrity, even when the engine gets really hot. As a result, you don’t get clutch fade or constantly have to adjust the clutch cable in the middle of your moto. The Rekluse TorqDrive system contains 12 friction plates in most Japanese-manufactured bikes, versus seven or eight in a OEM/stock configuration.” Additionally, the TorqDrive pack comes with steel lining clutch basket sleeves to eliminate wear and notching to the clutch basket tangs. Rekluse left no stone unturned. Rekluse developed a more durable clutch fiber compound while simultaneously improving the pad design for better cooling. The fiber material sits on a steel core, creating a complete package that drastically reduces clutch fade. TorqDrive technology can be found in the RadiusCX and RadiusX auto clutches, as well as the Core Manual TorqDrive and TorqDrive Clutch Pack manual editions. Read more about how TorqDrive works and find TorqDrive-equipped clutch systems here. Core Heat is the mortal enemy of an engine’s clutch. Rekluse confronted that problem head-on by developing their own hub, pressure plate and clutch cover. Made out of billet aluminum and designed around optimizing oil flow to lower clutch operating temperatures, Core is literally cool. Paden states, “We made the parts lighter in order to create less rotating mass. In comparison to the competition, what’s noticeable about our hubs and pressure plates are that they have very open profiles. The bottom and top of the hub have features that basically act as a dam for the oil. Oil that makes its way into the center hub is directed through the clutch plates. More flow reduces heat. The pressure plate is also open, and any oil that comes from the front side of the clutch system makes its way to the center clutch.” Rekluse Core billet inner hubs and pressure plates are designed to promote better oil flow and less rotating mass. A close inspection of an OEM/stock hub will likely reveal oil holes and features that are located in the profile where the drive plates would ride. With this design, the holes are potentially blocked, preventing oil from reaching the clutch plates. Rekluse found a solution. Paden explains, “The Rekluse-designed hub has the oil holes and features on the ribs themselves. There are features in the drive plates, which act like pockets, so the oil is able to flow to the clutch plates without restriction.” Taking it a step further, Rekluse created their own clutch cover that allows for roughly 50cc more oil capacity. More oil equals decreased operating temperature. Rekluse billet hubs have oil flow features directly on the ribs, adding another measure to clutch plate oiling. Also, Rekluse billet clutch covers allow for additional oil capacity to keep things cooler. Core technology is utilized in RadiusCX and Core EXP 3.0 auto clutches, as well as Core Manual TorqDrive and Core Manual clutches. Read more about Core technology and find Core-equipped clutch systems here. Automatic: What are your Options? Rekluse offers three automatic clutch options – RadiusCX, RadiusX, and Core EXP 3.0. RadiusCX is the Taj Mahal of automatic clutch systems, featuring a plethora of Rekluse’s latest technologies. It contains the best features, as far as cooling and auto clutch performance. If you are a clutch abuser, the RadiusCX is for you. Like the other auto clutch options, the rider can use the clutch lever for manual operation. Given that it’s full of benefits, this is also the most expensive auto clutch in Rekluse’s line ($1,019). The RadiusCX is the ultimate clutch package for riders desiring the auto clutch. It includes the Core billet components, TorqDrive technology, the EXP 3.0 disk, and the billet slave cylinder for DDS models (shown here). Find RadiusCX for your ride here. RadiusX is the little brother to the RadiusCX. Featuring EXP and TorqDrive technology, the system comes with the EXP disk and clutch pack, as well as the clutch basket sleeves. It does not come equipped with the Core billet components, and as such, is priced at $629. The RadiusX features EXP and TorqDrive to deliver a great auto clutch experience, it just does not include the Core billet components to keep the price point lower. Find RadiusX for your ride here. Core EXP 3.0 ($919) utilizes the EXP centrifugal disk, meaning that you can come to a complete stop in gear with clutch out and not stall the bike. The package also includes the Core billet parts. OEM/stock clutch plates are required with the Core EXP 3.0. The Core EXP 3.0 includes the EXP disk and all the Core billet components, but utilizes stock clutch plates. Find Core EXP 3.0 for your ride here. Manual: What Are Your Options? Rekluse also offers three manual clutch options – Core Manual TorqDrive, Core Manual, and TorqDrive Clutch Pack. Core Manual TorqDrive ($949) was designed for serious racers, used at the Supercross level on down to the amateur ranks. It has the most adjustments as far as tunability, and outstanding durability. The kit comes with Core and TorqDrive technology. Find Core Manual TorqDrive for your machine here. The Core Manual TorqDrive kit inludes Core billet components and TorqDrive technology. The power delivery improvement and added durability is nothing short of impressive. Core Manual is essentially a billet replacement for the stock hub and pressure plate. Some riders may prefer the feel of riding with OEM/stock friction plates. If that statement explains you, then the Core Manual is your best option. It is priced at $519. Find Core Manual for your machine here. If you want the durability and cooling characteristics of the Core billet components but prefer the feeling of stock clutch plates, the Core Manual is your clutch. The TorqDrive Clutch Pack takes the clutch pack used in the Core Manual TorqDrive and puts it into a stock hub and pressure plate. It’s very affordable, and a good alternative for racers on a tight budget. At $349, it doesn’t break the bank. Find TorqDrive Clutch Pack for your machine here. The TorqDrive clutch pack gives you the advantages of increased torque capacity without the added cost of billet components. The most affordable way to get all the holeshots. What the Professionals Run Rekluse’s list of sponsored riders reads like a who’s who in all of the major forms of two-wheeled off-road motorcycle racing series. In fact, Rekluse relies on some of the world’s best athletes for product development and durability. Given that Rekluse produces a variety of clutch applications, it makes sense that their fleet of sponsored riders have their particular favorites. The 2018 Monster Energy Supercross Champion, Jason Anderson, along with the rest of the Rockstar Husqvarna factory team, prefers the Core Manual system, which they pair with OEM/stock fiber plates. Dean Wilson opts for the TorqDrive clutch pack, as it easily drops into a stock clutch system. The Star Racing Yamaha team has been using the full Core Manual TorqDrive kit for roughly five years. In that span, the 250 program has won championships with Cooper Webb and Aaron Plessinger. Rekluse products go through multiple stages of testing and development, from in-house prototypes to detailed refinements with elite race teams. Dubbed “Mr. Versatility” by Racer X Illustrated, Ryan Sipes has competed in a bevy of different off-road disciplines over the past few years. From ISDE to GNCC, Sprint Enduro and event Flat Track, Ryan’s clutch of choice is the RadiusCX. Another GNCC racer, Ricky Russell, has used the RadiusCX system for the past year and a half. It makes sense, given that GNCC races are gruelingly long at three hours, where hand fatigue and engine stalling can be major issues. Paden explains that Endurocross riders tend to bounce back and forth between auto and manual clutch options. “Auto clutches were incredibly popular for several years in Endurocross, and then racers started gravitating to manual clutches. Right now, we’re in this state where guys are going back to the auto systems. It’s one of those scenarios where if one guy who is winning goes auto, the rest follow.” Given that a motorcycle clutch is a beneficial aftermarket modification, it is a change that is quickly picked up and copied by the competition. Believe it or not, there are some riders who prefer to race Supercross with an automatic clutch. Paden explains, “I have done back-to-back testing with top privateers in Supercross, and most post faster lap times with an auto clutch. They couldn’t believe it. That’s because an auto clutch makes the bike's power feel smoother.” Smooth doesn’t feel fast to most riders, but the stopwatch doesn’t lie. Paden believes that more riders will start preferring automatic clutches in Supercross over time. It’s not a crazy theory, given that roll speed is an important part of clearing jumps and being successful in Supercross. While an auto clutch may not 'feel' as fast to some Supercross riders, many of those that have tested it have posted faster lap times. Could we see a migration to auto clutches in Supercross? If you’re still unsure of which Rekluse clutch to install in your motorcycle, give the clutch experts a call at 208-426-0659, or browse the Rekluse website at www.rekluse.com.
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Whether you're racing or looking for increased performance out on the trail, there are a plethora of performance upgrades to consider to increase the power of your machine. Piston manufacturers like JE Pistons offer high compression piston options for many applications, but there are important merits and drawbacks you should consider when deciding if a high compression piston is right for your application. To better understand, we’ll take a look at what increasing compression ratio does, what effects this has on the engine, detail how high compression pistons are made, and provide a high-level overview of which applications may benefit from utilizing a high compression piston. Bumping up the compression in your motor should be an informed decision. It's important to first understand what effects high-compression has, the anatomy of a high-comp piston, and what applications typically benefit most. Let’s start with a quick review of what the compression ratio is, then we’ll get into how it affects performance. The compression ratio compares the volume above the piston at bottom dead center (BDC) to the volume above the piston at top dead center (TDC). Shown below is the mathematical equation that defines compression ratio: The swept volume is the volume that the piston displaces as it moves through its stroke. The clearance volume is the volume of the combustion chamber when the piston is at top dead center (TDC). There are multiple different dimensions to take into account when calculating clearance volume, but for the sake of keeping this introductory, this is the formula as an overview. When alterations to the compression ratio are made, the clearance volume is reduced, resulting in a higher ratio. Reductions in clearance volume are typically achieved by modifying the geometry of the piston crown so that it occupies more combustion chamber space. Swept volume is the volume displaced as the piston moves through the stroke, and clearance volume is the volume of the combustion chamber with the piston at top dead center. How does an increased compression ratio affect engine performance? To understand how increasing the compression ratio affects performance, we have to start with understanding what happens to the fuel/air mixture on the compression stroke. During the compression stroke, the fuel/air mixture is compressed, and due to thermodynamic laws, the compressed mixture increases in temperature and pressure. Comparatively, increasing the compression ratio over that of a stock ratio, the fuel/air mixture is compressed more, resulting in increased temperature and pressure before the combustion event. The resulting power that can be extracted from the combustion event is heavily dependent on the temperature and pressure of the fuel/air mixture prior to combustion. The temperature and pressure of the mixture before combustion influences the peak cylinder pressure during combustion, as well as the peak in-cylinder temperature. For thermodynamic reasons, increases in peak cylinder pressure and temperature during combustion will result in increased mechanical efficiency, the extraction of more work, and increased power during the power stroke. In summary, the more the fuel/air mixture can be compressed before combustion, the more energy can be extracted from it. Higher compression allows for a larger amount of fuel/air mixture to be successfully combusted, ultimately resulting in more power produced during the power stroke. However, there are limits to how much the mixture can be compressed prior to combustion. If the temperature of the mixture increases too much before the firing of the spark plug, the mixture can auto ignite, which is often referred to as pre-ignition. Another detrimental combustion condition that can also occur is called detonation. Detonation occurs when end gases spontaneously ignite after the spark plug fires. Both conditions put severe mechanical stress on the engine because cylinder pressures far exceed what the engine was designed for, which can damage top end components and negatively affect performance. Detonation and pre-ignition can spike cylinder pressure and temperature, causing damage. Common signs of these conditions include pitting on the piston crown. Now that there is an understanding of what changes occur during the combustion event to deliver increased power, we can look at what other effects these changes have on the engine. Since cylinder pressure is increased, more stress is put on the engine. The amount of additional stress that is introduced is largely dependent on the overall engine setup. Since combustion temperatures increase with increased compression ratio, the engine must also dissipate more heat. If not adequately managed, increased temperatures can reduce the lifespan of top-end components. JE's EN plating is a surface treatment that can protect the piston crown and ring grooves from potential damage caused by high cylinder pressure and temperature. EN can be an asset for longevity in a high-compression race build. Often, additional modifications can be made to help mitigate the side effects of increasing the compression ratio. To help reduce the risk of pre-ignition and detonation, using a fuel with a higher octane rating can be advantageous. Altering the combustion event by increasing the amount of fuel (richening the mixture) and changing the ignition timing can also help. Cooling system improvement can be an effective way to combat the additional heat generated by the combustion event. Selecting larger or more efficient radiators, oil coolers, and water pumps are all options that can be explored. Equipping the engine with a high-performance clutch can help reduce clutch slip and wear which can occur due to the increased power. High-level race team machines are great examples of additional modifications made to compensate for increased stress race engines encounter. Mods include things like larger radiators, race fuel, custom mapping, and performance clutch components. Let’s take a quick look at what considerations are made when designing a high compression piston. Typically, high compression pistons are made by adding dome volume to the piston crown, which reduces the clearance volume at TDC. In some cases, this is difficult to do depending on the combustion chamber shape, size of the valves, or the amount of valve lift. When designing the dome, it is essential to opt for smooth dome designs. Smooth domes as opposed to more aggressively ridged designs are preferred because the latter can result in hot spots on the piston crown, which can lead to pre-ignition. Another common design option is to increase the compression distance, which is the distance from the center of the wrist pin bore to the crown of the piston. In this approach, the squish clearance, which is the clearance between the piston and head, is reduced. Higher compression is commonly achieved by increasing dome volume while retaining smooth characteristics, as pictured here with raised features and deep valve pockets. Compression height can also be increased, which increases the distance between the center of the pin bore and the crown of the piston. A high-level overview of which applications can benefit from increased compression ratio can be helpful when assessing whether a high-compression upgrade is a good choice for your machine. Since increasing the compression ratio increases power and heat output, applications that benefit from the additional power and can cope with additional heat realize the most significant performance gains. Contrarily, applications where the bike is ridden at low speed, in tight conditions, or with lots of clutch use can be negatively impacted by incorporating a high compression piston. Keep in mind these statements are generalizations, and every engine responds differently to increased compression ratios. Below are lists of applications that may benefit from increasing the compression ratio as well as applications where increased compression may negatively influence performance. Applications that may benefit from utilizing a high compression piston: Motocross Supermoto Drag racing Road racing Ice racing Flat track Desert racing Motocross and less technical off-road racing are two of multiple forms of racing in which high-compression pistons can benefit performance due to higher speeds and better air flow to keep the engine cool. Peick photo by Brown Dog Wilson. Applications that may be negatively affected by utilizing a high compression piston: Technical off-road/woods riding Trials Other low speed/cooling applications Lower speed racing and riding may not benefit as much from a high-compression piston, as heat in the engine will build up quicker due to lessened cooling ability. Fortunately, if you’re considering increasing your engine’s compression ratio by utilizing a high compression piston, many aftermarket designs have been tested and optimized for specific engines and fuel octane ratings. For example, JE Pistons offers pistons at incrementally increased compression ratios so that you can incorporate a setup that works best for you. For example, high-compression pistons from JE for off-road bikes and ATVs are commonly available in 0.5 compression ratio increases. Assume an engines stock compression ratio is 13.0:1, there will most likely be options of 13.5:1 and 14.0:1, so that you can make an informed decision on how much compression will benefit you based on your machine and type of riding. From left to right are 13.0:1, 13.5:1, and 14.0:1 compression ratio pistons, all for a YZ250F. Notice the differences in piston dome volume and design. If performance is sufficient at an engine’s stock compression ratio, there are still improvements in efficiency and durability that can be made with a forged piston. Forged pistons have a better aligned alloy grain flow than cast pistons, creating a stronger part more resistant to the stresses of engine operation. In addition to forged material, improvements can be made on piston skirt style design to increase strength over stock designs, such as with JE’s FSR designs. JE also commonly addresses dome design on stock compression pistons, employing smoothness across valve reliefs edges and other crown features to improve flame travel, decrease hot spots, and ultimately increase the engine’s efficiency. Even if stock compression is better for your application; forged construction, stronger skirt designs, and more efficient crown designs can still provide improved performance and durability. If it’s time for a new piston but you’re still not sure what compression ratio to go with, give the folks at JE a call for professional advice on your specific application.
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In today’s challenging economic climate and this election year, the off-road motorcycle industry is moving slowly. Racing programs are being cut or even eliminated, and new bike sales are only up slightly. 2015 sales numbers have just been tabulated by the Motorcycle Industry Council (MIC) and at 730,000 units the total of motorcycle and ATV sales combined was only up 2.2% over 2014. Many riders are feeling the pinch and to that end we’re keeping our bikes longer and spending more money on maintenance and upgrade items than saving up for a new ride. Putting miles on off-road machines is hard on your equipment and your motorcycle requires at least the basic maintenance to get you through the day without mechanical or safety-related failures. With that in mind, we’ve put together 7 great inexpensive, cheap or even free ways to keep your older ride ready to hit the track or trail… #1 - EXHAUST PACKING: WHY YOU SHOULD CHANGE IT Experienced riders and racers know that a dirty, spooge-filled exhaust can limit an engine from reaching its full potential because you can just hear the difference once you spend enough time around these machines…but we never realized how much until we talked to the good folks at FMF Racing about how this maintenance items can impact riders and racers. Research by FMF has shown up to a 2 horsepower loss from blown muffler packing and that regular replacement can help restore top end power, improve throttle response and extend muffler life. Maybe the best reason is to reduce sound levels and help keep our riding areas open! To inspect your exhaust for packing issues, it’s best to remove the rivets and replace, depending on how many hours the machine is operating. Signs of needing replacement include excessive noise and pieces of baffle material leaving (being blown out) the canister. We’ve done this procedure many times and it’s rare that we see a muffler unit that isn’t past due for it to be done so if you stay on top of it you may always have an extra horsepower or two more than the rider next to you and that’s always a plus. FMF also has a good video explaining this process and you can see it here: REPACKING VIDEO #2 - OVERSIZED FOOTPEGS: GET CONTROL OF YOUR RIDE Photo: Footpegs have changed dramatically over the years If you’ve ever wondered why larger footpegs on off-road machines are so popular, you need to look back in the evolution of our machines…in the 60’s and 70’s even though motocross was becoming popular in the USA, the machines ridden had footpegs that were narrow, easily packed with dirt and mud, slippery when wet and weak. Controlling your motorcycle has a lot to do with being able to react quickly to obstacles when presented in real-time and being able to distribute your weight with the maximum amount of control and balance…and if you’ve ever had these issues due to inadequate pegs when riding you know they can make a fun day short or a short race really long when they aren’t right. To address this problem, aftermarket companies began to produce lighter, wider and stronger designs which incorporated open sections that were tapered in order to facilitate shedding debris faster, keeping the teeth clear for better boot to tooth contact. Fast forward to the present day and footpegs have achieved the status that they deserve and not only have the factory production pegs improved greatly, but some aftermarket examples like the Fastway Evolution III from Pro Moto Billet offer even more features like a reversible collar system that gives the capability to raise or lower the footpegs roughly 8-10mm, giving taller riders extra leg room, replaceable traction cleats for easy maintenance and adjustable camber for added comfort and control. #3 - BEARING REPLACEMENTS: BORING BUT EXTREMELY NECESSARY Bearings…they keep our machines rolling and operating smoothly but who wants to go through their ride looking for bearing issues? It’s certainly not as cool as installing a new pipe or engine upgrade…but it’s even more important! Bearings are the foundations upon which our machines run and roll and without them working correctly - disasters await. Bearing failures are always serious and can cost you many weeks of missed riding due to engine/mechanical issues, not to mention chance of serious injury to your person, so let’s see what we can do to avoid that drama entirely. Front to back some of the bearing sets you need to pay attention to include: front wheel bearings, steering stem, swingarm, shock linkages and rear wheel bearings as all of these take tremendous abuse in off-road motorcycles. Photo: Swingarm bearings live in a brutal environment We talked with the folks at Motion Pro (who make some of the best tools to make replacing these items easier) about what kinds of bearings need the most attention. “Kind of an open question, it really does depend on what part of the country, the type of riding, weather and maintenance…also how much power washing is done. Swingarm (and associated linkages) and PDS bearing seem to get the most abuse…….they are moving parts that are exposed to the elements. Steering stem bearings (and) races are probably the most neglected. Wheel bearing get hammered a ton and most home mechanics should be able to replace them on their own….’’ Motion Pro makes some of our favorite tools for these jobs like the Steering Head Bearing Race Driver and Deluxe Suspension Bearing Service Tool which are the right tools for the job and can make these procedures much easier and precise. #4 - TIRE PRESSURE: FIVE MINUTES CAN MAKE ALL THE DIFFERENCE Sometimes the simplest of maintenance items are the ones we overlook and one of those is certainly tire pressure, but it's vitally important and should not be overlooked. This small patch of rubber is your interface to the trail and holds the key to great handling in it's bag of tricks. We asked some questions of our friends at Michelin North America about off-road motorcycle tire pressures and some reasons why it should checked every time you go riding. How should riders properly check their tire pressures, should the tire be hot/cold? Pressure should always be checked before riding, especially if the motorcycle has sat, because air pressure decreases over time, typically at a rate of 1psi per month. It should be checked and adjusted when the tire is cold, meaning the tire’s temperature is equivalent to ambient temperature and riders should check pressure using an accurate, trusted pressure gauge. What type of installation and inspection should be done on both the tire valve and rim lock? When installing a tube, the valve should be positioned perpendicular to the rim (pointing directly towards the center of the wheel) and should be monitored regularly during the life of the tire to ensure that the valve stem is not beginning to lean. If the valve begins to lean, this indicates that the tire is slipping on the rim, and if not addressed, will result in a flat tire once the tube tears at the base of the valve. One common mistake riders make is tightening the external valve nut down against the rim which mechanically holds the valve stem in place, preventing the rider from seeing the warning signs of a leaning valve stem. Michelin recommends using the external valve nut as a locking nut against the valve cap to allow the rider to see any signs of the tire slipping on the rim and to ensure that the valve cap doesn’t come off, exposing the valve core to potential damage from debris. Photo: Pay close attention the the valve stem position What tire pressures are good for what? For example, should riders use less pressure for more traction? For motocross and off-road tire applications, tire pressure is a very subjective setting and often times riders’ base pressure settings vary depending upon their combined rider / motorcycle weight and the conditions in which they ride. For the new Michelin Starcross 5 tires, we recommend a base setting of 12.5 psi to 13.5 psi for optimum performance in a variety of terrain. Consumers can use a slightly lower pressure for muddy conditions as this will allow more casing flex of the tire, which can help facilitate mud evacuation from the contact patch. Lower pressure will increase size of the contact patch and can improve traction in certain conditions. For extremely rocky or challenging conditions that increase the chance of a puncture or pinch flat, consumers should use a slightly higher pressure to provide a more robust tire / tube combination. Are there any tools that are recommended like a low pressure gauge? Michelin recommends making air pressure adjustments for off-road tire applications in 0.5 psi increments to evaluate the change in tire performance and impact on suspension settings and it’s best to use a quality low pressure gauge to ensure these subtle changes are accurately measured. Photo: Use the correct equipment when checking tire pressures #5 - FORK OIL: WHATS INSIDE THOSE TUBES? Suspension is key to your motorcycle’s handling and safety and it’s made up of several parts that work in unison, including your front forks and rear shock. Many machines come setup for 160 pound riders and many riders never even change these settings, much to their detriment. Today’s multi-adjustable suspensions provide amazing compliance when tuned and serviced correctly, and provide correspondingly bad performance when overlooked. One area that we know escapes the inspection by many bike owners is the fork oil. Fork oil provides the ability for your forks to change characteristics rapidly as the terrain demands, through different valving and spring combinations that use fork oil for compression and damping features. We spoke to our friends at Race Tech for some advice on how to insure your fork oil stays fresh and up to the task. Race Tech recommends rebuilding your suspension with fresh fluids every 20-30 hours because an over-used fork fluid will begin to break down changing your damping characteristics and potentially allow expensive damage inside your suspension. All suspension fluids are not created equally; do your research. We prefer Race Tech Ultra Slick Suspension Fluids because they are slippery, temperature stable, long wearing and non-foaming suspension fluid. As far as, weight/oil level, it can be found easily on the Valving Search per model. Photo: Forks are precision instruments and should be serviced regularly for best performance If thinking about upgrading or working on your suspension, check out the to the Tech Support button at RaceTech as there is some good information there. #6 - BRAKING MAINTENANCE: TO GO FAST YOU NEED TO STOP FAST Another often overlooked player in the off-road motorcycle equation is the braking system(s). Many riders don’t address the brakes until braking performance suffers to the point of being dangerous. Conditions that can adversely affect braking performance can include master cylinder reservoir fluid level dropping rapidly, brake noise modulating and brake lever and/or pedal travel increasing when applying the brakes. There are different aspects of your brakes you need to keep on top of and the first are the actual brake pads and rotors, because they see the most wear and have a such an important role in slowing and stopping your machine. Photo: Many different components must be inspected to insure braking performance As your brake pads wear, the metal backing will eventually surface and start to actually contact the rotor, causing damage and many times requiring a replacement so you can’t allow this to happen. Rule of thumb is to change your brake pads at the first sign it’s required and you can check your owner's manual for specs on at what point brake pads should be changed. It’s easy to see approximately how much material is left on the pads and it’s a usually simple procedure to drop the pads out of the calipers and check the thickness when you think you’re getting close to the wear limit. Brake rotors can be visually inspected for signs of stress cracking and warping before riding and these conditions can sometimes be felt while applying the brakes. Run your fingernail across both sides of the disc…are there any deep grooves or excessive scoring on the surface? Are there any visible cracks? If you see any of these conditions, you’ll want to find out why they’re happening and correct the situation immediately. Next up is to visually inspect your brake lines and all associated fittings for any signs of seepage or leaking of brake fluid. The fluid must be absolutely clean and free of any type of contaminants and if not, must be replaced immediately. Brake fluid is also corrosive to painted surfaces and can react with other types of chemicals in a negative manner so caution must be used during the handling and storage. Check the top(s) of the brake reservoirs…are they clean and dry and hardware tight? Is the fluid at the appropriate level as specified in your owner’s manual? Does it look clean and clear? If not, time to delve deeper into the problem and fix it before riding again. Brake fluid comes in different types and it’s important you use the correct type and volume as specified in your owner’s manual…failure to do so can result in damage to both expensive components as well as your body after not being able to stop! # 7 - SETTING YOUR SAG: YOU NEED AN ATTITUDE ADJUSTMENT One of those mystical procedures in our sport is this thing called “setting your sag” and I never see riders doing it! I’ve done it many times but still don’t know if I’ve got it down perfect and it’s not something I look forward to doing, but when I do get it done, I can feel the results. The rear of the bike is especially compliant with my light weight and the rebound fells like its hugging the ground on the smaller stutter bumps… as well as being easier to set up into fast sweepers and switchbacks where the bike loads and unloads the suspension fairly rapidly. So it’s worth doing and doing it right…we asked the experts at MoTool about setting sag properly, why you should do it and a bit about their new digital Slacker scale which can make this task a lot simpler, faster and with more accuracy. Riders should be concerned with setting their sag because every bike is designed to sit in a certain posture regardless of the rider’s weight and this determines how the bike handles. The suspension should compress or “sag” the same amount for every rider. The key is to preload the springs more or less depending on the rider. Sometimes you may even require softer or stiffer springs depending on your weight and the particular bike. Sag can also be adjusted for varying conditions. For fast conditions, run a little more sag in the rear so the bike is stable at speed or, for tighter conditions, you can run less sag which produces a steeper fork rake and thus the bike turns better. This is the most misunderstood and overlooked settings when it comes to suspension setup. If the bike is not setup properly it will become unpredictable and unsafe. This setting is definitely as important for casual play riders as it is for seasoned pros as it assures it will perform as the manufacturer intended. How is it done conventionally? Conventionally it took at least two people to take the measurement. One, taking the measurements and two, the rider that has to be on the bike. A measurement was taken with the suspension unloaded then another was taken with the rider. The second measurement was subtracted from the first to get the actual sag measurement. It always required at least another person and there was a lot of room for error in how/where it was measured and in making sure the math was right. Photo: The MoTool Digital Slacker sag tool How is it done using the Motool Slacker digital sag scale? With Slacker, you simply put the tool on the bike with the suspension unloaded and turn it on or you can use the new Auto Zero feature if the suspension is not unloaded when Slacker is mounted. Then just mount the bike and it will show you the measurement in real-time on the remote display as well as the main unit which is attached to the axle. This allows a single person to quickly and easily take a precise measurement by simply leaning against a wall or vehicle with an elbow to balance and looking at the remote LCD display. Even if you have a helper, Slacker is much faster and more accurate than a tape measure or sag stick. No matter how you do it, you should be checking your sag regularly and adjusting for different conditions pretty much every ride. Note: Setting your sag can sometimes be a long and complicated procedure, so our friends at Race Tech have devoted a page to show you how to do it. In conclusion, maintaining your off-road motorcycle is vitally important to staying safe and being fast while piloting your iron steed. By properly keeping maintenance items as described above at the top of your riding checklist, you not only insure you maintain the highest performance your bike is capable of, but also increases the safety, handling and control of your machine…it just can’t be overlooked as your life can depend on it. Of course, this list isn't meant to be exhaustive; we know there are more ways to improve the feel of your bike. That's where we'd like to hear from you! Hit us up in the comment section below and share your methods for bringing back the like-new performance and feel of your not so new ride.
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United by Power: Episode 3 – Cooper Webb, Jason Anderson & Alex Martin
NoFiddyPilot posted an article in Articles
September 28, 2016 – (Motor Sports Newswire) – As the drama unfolds in Italy, Team USA makes a full on effort to combat the challenging teams for the top spot at MXoN. Jason Anderson escapes a near tragic crash and Cooper Webb is forced to deal with pressure from Team France. In spite of the poor gate choice, Alex Martin still fought through the pack each moto to secure top 10 finishes. The Team gave it everything they had through the adversity the weekend brought. Despite the hardship, Team USA still made the podium for a 3rd place finish. About FMF Racing Established in 1973, FMF Racing is one of the most dominant and influential brands in the world of Off-Road Motocross Racing. Founded by Don Emler in his Hawthorne, CA garage, the brand’s steadfast dedication to supporting the sport, along with its athletes and partners, has earned the respect and loyalty of industry consumers and insiders. From cutting-edge design to efficient manufacturing, sourcing, marketing, operations and distribution, FMF strives to elevate performance in every facet of the business. FMF Racing’s iconic red-and-yellow logo is still fueling the growth and passion for the sport of motocross more than 40 years later. The family-owned and operated company also features top level world-class race teams that continue to dominate the podium at events around the globe. Find us at: http://instagram.com/fmf73 | http://facebook.com/fmfracing | http://youtube.com/fmfracing1973 About Rockstar Energy Drink Rockstar Energy Drink is designed for those who lead active lifestyles – from Athletes to Rockstars. Available in over 25 flavors at convenience and grocery outlets in over 30 countries, Rockstar supports the Rockstar lifestyle across the globe through Action Sports, Motor Sports, and Live Music. For more information visit: www.RockstarEnergy.com Find us at: http://Facebook.com/Rockstar | http://Twitter.com/RockstarEnergy | http://Instagram.com/RockstarEnergy | http://YouTube.com/Rockstar Source: FMF Racing -
Buying a used dirt bike can be a gamble no matter how you approach it, so always make sure that you give your potential new bike a thorough inspection before deciding whether or not you intend to buy it. Faults can be difficult to spot, or easy to miss at a glance - and you don’t want to be discovering them after you’ve handed over your cash, and driven off into the sunset with your new bike. It’s often a smart idea to bring along someone who has a good understanding of vehicle mechanics with you when you go to your inspection, and don’t forget to ask the bike’s previous owner why they have decided to sell their bike. Consider what kind of riding you will be doing before you head out to buy your bike. There are endurance bikes for trail and bush rides, on and off road bikes, as well as purpose built motorbikes. Make sure you know which is right for you. Avoid buying a bike that’s too powerful, as you don’t want your lack of control over your own vehicle to slow you down. Check that the rims are straight, and be sure to spin the wheels to ensure that they don’t wobble. Check for dents and cracks, and ensure that all the spokes are adequately tightened. Also ensure that there are no cracks or chips in the bike’s plastic. Be sure to give the bike a proper inspection. Examine the wheel bearings, excessive arm swing movement, and that the fork seals aren’t leaking. Sit yourself astride your bike, and test the suspension under your weight to ensure it’s moving freely. Turn the handlebars back and forwards to ensure they have a full range of available movement. Check the handlebars to ensure they’re straight, double check the foot controls and footpegs for damage, and for bends, and don’t forget to look over the radiator coolant to make sure it’s blue or green. Finally, start the bike, and see how difficult it is to start up. If everything seems to be in check, then you might have just found yourself a great deal on a well-maintained bike! Before you take your bike out for a spin, make sure that you have protective motocross gear to keep you from injury. Sources: http://www.dirtbikeaustralia.com.au/articles/Used-Dirt-Bike-Sales.html https://www.your-adrenaline-fix.com/used-dirt-bikes-for-sale.html http://www.mxstore.com.au/blog/helpful-advice-handy-tips/tips-on-buying-a-new-or-used-dirt-bike/#
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Chances are that your gear is caked in mud by the end of the day. While a thorough cleaning is necessary, you run the risk of damaging the your outfit in the process. Alternatively, you don’t want to be wearing dirty gear because you’re afraid of ruining the material. Whilst you should always adhere to the specific washing labels your gear comes with, these tend not to be detailed. Luckily, there are basic guidelines you should follow while washing your gear to ensure you get maximum cleanliness with no harm done. Act fast Starting the process early is essential in cleaning your gear. Avoid crumpling your outfit as this allows the dirt to sink in. Instead, try to remove as much as dirt as you can before properly washing it. This can be done by hosing off the mud under a low pressure. For stubborn stains, use a soft brush with cold water and a mild detergent. Avoid using excessive force as this can deteriorate the durability of your gear. Oxygenated detergent You should be wary of using oxygenated detergent when washing your gear. While it’s useful for the extra lift it gives to stains, its active ingredients can dry out the leather knees. Over time, this will make them unsafe due to cracking and splitting. Turning your gear inside out and soaking with a mild, non-abrasive detergent is gentler than using oxygenated detergents without compromising on hygiene. Machine washing After removing as much dirt as you can, wash your gear in the machine under a cold wash and cold rinse. Some riders are tempted to pressure clean their gear or wash it under a more rigorous cycle, but this runs the risk of crumpling or fading your gear. It’s also powerful enough to push the oils out from the leather knees, compromising their flexibility. Also avoid washing your gear with bleach, as this will fade the colour. Drying Tumble drying your gear after it’s finished washing can ruin all the careful cleaning you’ve done to this point. Hang it to dry in a well ventilated area out of direct sunlight. This will allow the material to breathe and protect the colours from fading prematurely. After it's dry, pack away neatly and never iron it out as this can melt the fabric. Sources: http://www.mxstore.com.au/blog/helpful-advice-handy-tips/how-to-wash-your-motocross-gear/ http://motocross.transworld.net/features/tuesday-tip-cleaning-your-riding-gear/#vqqGBwtO8xRpissS.97 http://www.motoonline.com.au/2010/08/05/fast-fix-cleaning-motocross-boots/
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IRVINE, CA – October 15, 2015 – (Motor Sports Newswire) – The Monster Energy® Kawasaki racing team looks to continue its championship winning ways with former champions Eli Tomac and Wil Hahn. Tomac, the 2012 250cc Supercross® West Region Champion and 2013 250cc Motocross Champion, continues to be a top competitor in the premier supercross class including winning supercross and motocross races during his first two years in the premier class. Hahn is beginning his third campaign in the premier class after capturing the 2013 250cc Supercross East Region Championship and is poised to collect podium finishes in 2016. Both will compete on the championship proven KX™450F as they look to continue Kawasaki’s winning legacy. “The new KX450F provides a great platform to build champions,” said Dan Fahie, Monster Energy Kawasaki Team Manager. “I believe we are poised to have a successful 2016 season with Eli and Wil under our tent. Both riders have proven to be top contenders in the 450 class and they are just as enthusiastic as we are to get back to racing and on top of the box.” Tomac brings with him an impressive resume that includes a 250cc Supercross West Region Championship, a 250cc Motocross Championship, three AMA premier class Supercross race wins, 11 podium finishes, second overall in the 2015 AMA Monster Energy Supercross season and two overall wins, two overall podiums and five moto wins in the 2015 Pro Motocross season. The Monster Energy Kawasaki racing team has been the most dominant supercross and motocross team in the last decade with eight combined AMA titles. “Joining Monster Energy Kawasaki has always been a goal and dream of mine,” said Tomac. “I feel like with a bike and chassis as good as the KX, plus a team totally dedicated to the 450 class, we should be able to do big things in the near future. It’s a new team, new bike and a new year of racing. I can’t wait to get back at it.” With all five riders returning in 2016, the Monster Energy/Pro Circuit/Kawasaki racing team is also looking to reaffirm their position atop the podium. Adam Cianciarulo returns for his third full year after a podium and five top ten finishes in the 2015 Pro Motocross season, along with four-time Arenacross® champion Tyler Bowers for his second full season. Chris Alldredge also returns following an impressive first full season of professional racing with the Monster Energy/Pro Circuit/Kawasaki racing team and will be joined by Arnaud Tonus who turned heads during his U.S. debut last year. Beginning his second year is Joey Savatgy who scored his first professional overall win at the Unadilla motocross round and ended the year third overall in the 250cc Motocross Class standings. The Monster Energy/Pro Circuit/Kawasaki team is one of the winningest supercross and motocross teams with 29 AMA titles. “We are looking forward to starting the 2016 season at full strength,” said Mitch Payton, Pro Circuit owner. “I know every one of our riders is capable of winning races and I expect nothing but the best from them every weekend.” Hahn will debut the 2016 KX450F at the Monster Energy Cup on October 17th in Las Vegas.
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Series’ Lone Visit to America Marks 2015 Finale SAN BERNARDINO, CA – September 2, 2015 – (Motor Sports Newswire)- In just a matter of weeks, the hills surrounding legendary Glen Helen Raceway will come to life with a global showcase of motocross talent. On September 19-20, the FIM Motocross World Championship (MXGP) will make its anticipated return to Southern California for the 18th and final round of the 2015 season – the Monster Energy MXGP of USA, presented by Chaparral. This exclusive stateside visit for the World Championship will feature a convergence of American and international stars, setting the stage for a must-see battle of racing supremacy. Photos by Monster Energy With newly crowned MXGP Champion Romain Febvre leading the way aboard his Yamaha Factory Racing Yamalube machine, several of America’s biggest names from the Pro Motocross Championship are prepared to go head-to-head against Europe’s best in a one-time-only showdown. While the premier MXGP class will be spearheaded by the likes of World Championship veterans like Febvre, Red Bull KTM Factory Racing’s eight-time world titleholder Tony Cairoli, and Team HRC’s Gautier Paulin, the lineup of Pro Motocross stars is impressive. Newly crowned MXGP Champion Romain Febvre. Photo: MXdose.com The Rockstar Energy Husqvarna Factory Racing duo of Jason Anderson, capping off his first full season of premier class competition, and Christophe Pourcel, a former World Champion, each garnered overall podium results during the Pro Motocross season. Monster Energy Kawasaki’s Josh Grant is the hometown favorite, hailing from nearby Riverside, and will swing a leg over the Factory Kawasaki one last time in 2015. Red Bull KTM’s Dean Wilson will continue his comeback from a serious knee injury and make just his fourth motocross start of the season, while Davi Millsaps will make his highly anticipated debut for BTOSports.com KTM, just a handful of weeks after signing with the team. Hometown rider Josh Grant, from Riverside, California, will be one of many talented Pro Motocross competitors taking on Europe's best. Photo: Monster Energy Kawasaki Serving arguably the most intriguing role of the Pro Motocross contingent is Yamalube/Star Racing Yamaha’s Cooper Webb. After racing to a pair of overall victories in the 250 Class this summer, the newest member of the AMA US Motocross Team for the FIM Monster Energy Motocross of Nations will make his 450cc debut at Glen Helen in the MXGP division. In addition to the excitement surrounding which rider will emerge victorious in the world’s showcase class, the wild MX2 division is sure to produce unpredictable competition. With the championship hunt coming down to the wire between Honda Gariboldi’s Tim Gajser, Red Bull KTM Factory Racing’s Paul Jonass and Monster Energy DBT Kawasaki’s Max Anstie, there will be plenty of drama in the battle to crown a champion. However, with the addition of former world champion and Red Bull KTM’s Pro Motocross Championship runner-up Marvin Musquin, the Troy Lee Designs/Lucas Oil/Red Bull/KTM duo of Jessy Nelson and Shane McElrath, as well as a competitor from legendary Monster Energy/Pro Circuit/Kawasaki stable, a little added shakeup to the title fight is to be expected. Cooper Webb will make his 450cc debut at the USGP in preparation for his inaugural trip to the FIM Motocross of Nations in France. Photo: ProMotocross.com Simply put, with such a strong contingent of home soil stars ready to converge for a head-to-head battle against an incredibly talented international field, the stage is set for the Monster Energy MXGP of USA at Glen Helen Raceway to cap off the racing season with an event no motocross fan will want to miss. Pro Motocross Rider List: MXGP Jason Anderson - Rockstar Energy Husqvarna Factory Racing Josh Grant - Monster Energy Kawasaki Davi Millsaps - BTOSports.com KTM Christophe Pourcel - Rockstar Energy Husqvarna Factory Racing Cooper Webb - Yamalube/Star Racing Yamaha Dean Wilson - Red Bull KTM MX2 Shane McElrath - Troy Lee Designs/Lucas Oil/Red Bull/KTM Marvin Musquin - Red Bull KTM Jessy Nelson - Troy Lee Designs/Lucas Oil/Red Bull/KTM TBD - Monster Energy/Pro Circuit/Kawasaki **Participating riders subject to change.** The battle for the MX2 title will come to an end at Glen Helen. Photo: Dirtbikerider.com Tickets to the Monster Energy MXGP of USA start at just $70 for three-day access to the ONLY opportunity to see the stars of Europe in action. The event will feature two full days of on-track action, with practice and qualifying races on Saturday, September 19, setting the gate for final motos on Sunday, September 20. Tickets: Sunday Only Access - $50 Adults / $30 Kids (ages 6-12; 5 and under FREE) 3-Day Admission - $70 Adults / $40 Kids (ages 6-12; 5 and under FREE) Holeshot Club/VIP - $300 Adults / $150 Kids (ages 6-12) Additional Purchase Options (DO NOT include admission) Rally Towel Viewing - $5 Grandstand Seating - $10 Paddock Pass - $20 Tent Camping - $50 RV Parking - $90 **All sales are final. No Refunds. Taxes and processing fees do apply.** Defending MX2 World Champion Jordi Tixier will wear the number one plate one last time at Glen Helen. Photo: Monster Energy Event Schedule: Saturday, September 19 10:45 a.m. MX2 Free Practice 11:15 a.m. MXGP Free Practice 1:00 p.m. MX2 Timed Practice 1:35 p.m. MXGP Timed Practice 3:00 p.m. MX2 Qualifying Race 4:00 p.m. MXGP Qualifying Race Sunday, September 20 10:20 a.m. MX2 Warm Up 10:40 a.m. MXGP Warm Up 12:00 p.m. MX2 Race 1 1:00 p.m. MXGP Race 1 3:00 p.m. MX2 Race 2 4:00 p.m. MXGP Race 2 Additional information about Glen Helen Raceway can be found at www.GlenHelen.com. Also “Like” the Glen Helen Raceway Facebook page and “Follow” @GlenHelenRacing on Twitter.
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Everywhere you look these days you see vintage motocross machines…on the web, at the track for practice days, in museums and especially at vintage racing events. Once the territory of old-school 3” suspension machines, times have rolled on and now vintage bikes can include monoshocks and 12” suspensions. So why is it so popular? First off, many of us who grew up in the 70’s and 80’s riding are yearning for nostalgia, a way to recreate those good old days when even the pros raced out of oversized vans. This harkens back to the old days for many riders who moved on after their brief riding and racing careers and hung up their old Jofa mouthguards and JT jerseys, but now have the financial freedom to pursue their old dreams of glory, using the machines they owned or raced against in the wild and wooly days of off-road motorcycle racing. (Photo Credit: Tom McKelvey) And around this new found passion for old time fun was formed a loose group of promoters, racers and restoration specialists who have risen up to meet the demand. And this support is helping propel this unique section of our sport to new levels of acceptance as well as providing the much-needed technical support and reproduction parts essential to expanding the ranks of both racers and spectators. In terms of spectators, these vintage race events have a much more hands-on feel and are generally more intimate affairs than most big race meets, offering up close and personal viewing of both the exotic machines and the riders who raced them. Many of the enthusiasts involved would have no problem explaining in detail how a laid down shock or boost bottle was supposed help their machine back in the day, and most machines are on display during the day for all to see and admire. Many parents who are riders want to show their offspring how the sport started, what Dad (or Mom) raced on, and seem to want to impart how hard it was to go fast on these older machines with their narrow powerbands and marginal suspensions. This can give the younger generation a chance to appreciate where the sport started and how far we’ve actually progressed since “back in the day”. We’ve assembled a lot of insight and some available resources for ThumperTalk readers so if you want to get a good idea of what’s going on in the vintage motocross scene, read on. We spoke to the experts at the AHRMA (American Historic Racing Motorcycle Association), MX Rewind (UnadillaMX), CALVMX (California Vintage Motocross Association) and restorers like ECVMX (East Coast Vintage Motocross) as well as a host of riders to see just why vintage motocross taking our sport by storm. AHRMA (AMERICAN HISTORIC RACING MOTORCYCLE ASSOCIATION) Different organizations recognize different standards when it comes to vintage motocross motorcycles. The AHRMA, which has emerged as the defining authority when it comes to vintage motorcycle racing, has two distinct categories: Vintage Motocross featuring motorcycles built before 1975 and according to AHRMA: “This time period may not be the very beginning of the sport, but marks the period of international recognition after WWII. It ended in the mid-1970s, and is considered to many around the world as one of the greatest eras of the sport.” They continue: “At the beginning of this time period, the machines raced were basic transportation-based models with slight modifications. They were raced over farmland settings with natural challenges. Higher speeds, terrain and off-camber turns provided the main challenges on these tracks that are typical of those used into the early ‘70s. Our era ends with the advent of specially designed racing machines on specially prepared tracks” Post Vintage Motocross featuring machines which are post-1975 and according to the AHRMA: “Purpose-built motocross racers which introduced many technologies, from the very first long-travel suspension through to the advent of water-cooled engines and linkage-controlled rear suspensions found at the end of this exciting time in motocross.” So “vintage motocross” actually encompasses many different eras of motorcycles, from older 4-stroke off-road twins to 2-stroke water cooled rocket ships, and really it has something for everyone. If you look at the classes just about every type of older off road machine has a place to race. (Photo Credit: Tom McKelvey) MX REWIND (UNADILLA) We spoke with Jill Robinson at the holy grail of outdoor tracks, Unadilla, and she gave is the following insights into the MX Rewind event that has gained immense popularity over the last few years, making it the premier vintage motocross meeting in the Northeast US. Jill said “MX Rewind is a full weekend event which celebrates dirt bike racing and its history. We start Friday morning with AHRMA vintage cross-country racing and segue into the afternoon with AHRMA post-vintage cross country racing. This year, we added a new event, AHRMA vintage trials to Friday’s line up. Saturday begins two solid days of vintage and post vintage motocross racing.” She continued: “The weekend is structured to not only be full of vintage racing but to also recognize and celebrate the history of the sport. Our legends also really help bring the history to life. We wanted the weekend to certainly highlight racing but to take it a step further. To that end, we have displays, a swap meet area, and night-time activities that concentrate on the past and how we got to the present. Meet and greets, autograph time, and bench racing with the legends is also a big part of the weekend.” “MX Rewind always amazes us. For the whole weekend, we are surrounded by racers and their families who love to keep the historical side of the sport alive. They treasure their bikes but love to show them off and ride them. They work hard to make sure that they are as close to, if not, 100% authentic. That isn’t easy for bikes that are over forty years old. But they are dedicated and put their heart and soul into it. They walk up to the legends and say “remember when” and get into racing discussions and, depending upon the legend, technical discussions that are certainly not superficial. They help each other out and they are serious about what they are doing but with a lets-have-fun-and-enjoy-ourselves attitude.” TT: Who are some of the big names participating at MX Rewind? According to Jill Robinson, some of the big names that have attended the MX Rewind event are: Brad Lackey, Danny LaPorte, Trampas Parker, Ron Lechien, Donnie Hansen, Barry Higgins, John DeSoto, Tony D, Guy Cooper, Jeff Stanton, Gary and Dewayne Jones, Mark Barnett, Mick Andrews, Jimmy Weinert, Warren Reid, John Dowd, Doug Henry, Larry Maiers, Gunnar Lindstrom, Carlo Coen, Bruce Stratton, John and Jack Penton, Sonny DeFeo, Pat Maroney, and Gary Bailey. She continues: “All but a small number of our legends have raced either as a team captain in the Team Cup Challenge or raced as individuals in several of the classes. Honestly, Guy Cooper can still ride the wheels off of anything you put him on!” So, if you’re looking to get it all in one place, MX Rewind at Unadilla is a great place to introduce yourself to the vintage motocross scene. With racing, displays and vendors coupled with one of the most historic AMA national tracks as the backdrop, MX Rewind at Unadilla is a mecca for vintage motocross fans. AMA VINTAGE MOTORCYCLE DAYS (MID-OHIO) Another cornerstone event in the vintage motocross world is Vintage Motorcycle Days held at Mid-Ohio. This is the big daddy of these types of events in our minds and is billed as “North America's largest motorcycle swap meet”. I’ve never seen so many antique and vintage to present day motocross machines in one place before, even the swap meet portion is mind-blowing, with every brand and model bike you ever remember is represented. According to the AMA: “Every year, tens of thousands enthusiasts join the AMA and the Motorcycle Hall of Fame Museum, and nearly 1,000 independent vendors at vintage motorcycling’s biggest bash. The event includes racing, the country's largest motorcycle swap meet, seminars, stars from the sports past and present, bike shows and more, all designed to recapture a simpler time and remind us what's fundamentally cool about riding motorcycles.” We would have to agree with that. The show area is amazing and the Motorcycle Hall of Fame tent and the Classic Club displays are always incredible with some of the country’s best restored machines on view. Racing at Vintage Days is the focus and there is a lot of friendly competition. The off-road courses consist of many disciplines, including motocross, flat-track, trails and hare scrambles so the variety of racing machines is immense. If you’re looking for a place to start learning (and maybe even racing) vintage motocross, the AMA Vintage Motorcycle Days would be a great place to start. CALIFORNIA VINTAGE MOTOCROSS (CALVMX) CALVMX is a huge vintage motocross club based in the southwestern US and they race at some of the most revered tracks from back in the day…today. Tracks like Carlsbad, Cahuilla Creek and Glen Helen to name a few. We took some time to talk to Frank Vrettas from CALVMX about how the organization works and what they do to help further the sport: TT: Why was CALVMX formed and how many members are there? FV: CALVMX was formed to offer a venue for racers of all ages to have an opportunity to compete in a more relaxed atmosphere and the emphasis on having fun and preserving the sport of vintage racing. It was our goal to showcase bikes made from the 50's on up and let younger riders see how motocross machine evolved over the years. Many of the racers are ex racers from the 60's, 70’s and 80's. CALVMX has over 250 members and among them are moto-legends like Marty Smith, Bob Hannah, Marty Tripes, Preston Petty, David Bailey and Malcolm Smith. TT: What are the most popular classes raced? FV: Vintage 250cc bikes (pre 1975), then GP 1 class (pre 1980) classes are among the most popular. (To see the class listing, click here: CALVMX classes – Ed.) TT: Biggest event of the year? FV: That would be the AHRMA National which is two times per year and sees over 300+ entries. ThumperTalk readers may want to note that this year we are hosting a very large event, the 40 year anniversary of Women's Motocross event on September 6th in conjunction with AHRMA National at Glen Helen, and we expect well over 400 entries for this event. EAST COAST VINTAGE MOTOCROSS (ECVMX) Vendors such as East Coast Vintage Motocross (ECVMX) are helping lead the charge in the vintage restoration arena. ECVMX is owned and operated by Chris, Jim and Jason Weaver and the vintage moto restorations are performed by their house restorers Jim Pennington and Michael Baker. Photo: ECVMX Facebook We spoke to Jason about what was going on at ECVMX and his thoughts on vintage motocross racing: TT: Why would someone come to ECVMX to have their vintage bike restored? JW: Our family has been involved in some sort of motorsports activity since the early 70's. We have motocross, flat track, and even sports car racing backgrounds. Like most of you out there we have owned the CR's - KX's - Bultaco's - Maico's and Husky's that we wish we would have held on to! Our passion is now finding these bikes, bringing them back to life, and letting their new owner's enjoy them for years to come. Jim Pennington has been with us since we started as a hobby business back in 2010. He has grown as we have grown - and his expertise has followed suit. He can handle pretty much anything need on any make off road machine and Michael Baker has just started with us as our second in house technician - is a graduate of Wyotech - and has an extensive 2 and 4 stroke background. He has quickly gotten up to speed on the "quirks" of 40+ year old motorcycles and we are glad to have him onboard. TT: What is the most popular bike or class/size of bike restored? JW: We restore more 1983 Honda CR250/480's than any one bike. They are a very dependable and popular model in the AHRMA classes - and are easy to obtain parts for as well as being very competitive. The European bikes are popular as well - many vet riders lusted over that Maico or CZ back then but couldn't afford it - but now have the means. TT: Why do you think vintage racing is so popular? JW: “I think there are a number of reasons that Vintage MX has stayed strong and is continuing to gain popularity. One being is the relative affordability of the sport. If you compare the overall spend to sports car racing / collector cars / boats etc - a $2500 vintage bike looks very affordable. Not to mention the fact that most of these bikes are actually appreciating or at a minimum holding their value. We are in a prime era of the guys who rode in the late seventies early 80's now getting interested again in riding the 40+ and 50+ age classes. Photo: ECVMX Facebook In conclusion, vintage motocross racing is becoming a big part of our sport and seems to growing every day with the meets getting larger and the classes expanding to accommodate almost all the older machinery racers may have stashed in their garage. If you’re ready to explore more of the vintage racing scene, visit the links below. AHRMA (AMERICAN HISTORIC RACING MOTORCYCLE ASSOCIATION) MX REWIND (UNADILLA) AMA VINTAGE MOTORCYCLE DAYS (MID-OHIO) CALIFORNIA VINTAGE MOTOCROSS (CALVMX) EAST COAST VINTAGE MOTOCROSS (ECVMX)
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Here is a quick and easy way to remove oil seals from the engine or transmission cases without splitting them. Watch the video for the step by step process. This technique only works on seals that can be installed from the externally (outside) Video WITH the explanation of what I am doing and the tools I am using http://www.dailymotion.com/video/x190kpb_crankshaft-seal-removal-replacement Original video (Edit: Youtube forced an audio swap which took out my explanation of what I am doing in the video)
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I pulled this from another forum. Wall of text, but informative. A good read from Tim Harral on 2 stroke karts. Since Birth It's a common sight. You see a kart in the pit with the cylinder head off. A group of technical "guess men" are assembled in a circle passing around a seized piston as if touching it can give them greater insight as to the reason for it's failure. Unfortunately, when this whole mess of parts gets dragged own to the shop, the engine builder may not be able to provide much more insight unless he is very familiar with that particular engine's "sources of seizure". It's a lot to ask. Even among engine builders, there's plenty of confusion about what causes a particular piston to seize. The following information will help to dispel some myths, and shed some light on the understanding of piston seizures. The objective of this article is to make piston seizures a part of your past. Some fundamentals: Many people believe that piston seizures occur when engine heat causes the piston to expand larger than the size of the cylinder bore .... This is not true. If you could freeze your engine "in motion" in the middle of a long full throttle pass, and disassemble it for micrometer measurement, you would find the piston skirt to measure at a 0.0000 to 0.0005" or so press fit into the bore. That's right, a slight press fit! The reason that it doesn't seize is because the premix oil has such a terrific film strength that it acts as an unremovable buffer between the piston and the cylinder. That is, the bare metal surface of the piston never actually touches the bare metal surface of the cylinder because the oil stays between them. Many mechanics have experienced this phenomenon while cleaning a freshly bored cylinder. Completely dry without cleaning solvent, the piston moves through the bore with difficulty. After rinsing the piston glides all the way through with no resistance at all. This is because the solvent acts as a film between the piston and cylinder. A piston seizure can only occur when something burns or scrapes away the oil film that exists between the piston and the cylinder wall. Understanding this, it's not hard to see why oils with exceptionally high film strengths are very desirable. Good quality oils can provide a film that stands up to the most intense heat and the pressure loads of a modern high output engine. The difference between seizure and scoring: Seizure and scoring are two different stages of the same problem. When the oil film on a cylinder is momentarily burned or brushed away, the metal surfaces of the piston and the cylinder wall will actually touch. When this happens, there is a sort of scraping that takes place between them. When the oil film is resumed, the marks from this scraping will often remain on the piston and (or) the cylinder wall. This momentary scraping or "scoring" seldom causes any permanent or performance robbing damage. No significant damage takes place because the oil film is resumed before the piston and cylinder have a chance to start exchanging material onto one another. Scoring is commonly seen on the piston face directly below the piston ring end gaps. The blast of combustion can get between the large end gap of a worn out ring and burn the oil off the piston and cylinder in that area...Hence the surface scoring. In most cases, score marks can simply be sanded off of the piston and cylinder. However when ever you see scoring, it's a good idea to find the source so that it doesn't develop into a full blown seizure. Seizure is a case of scoring where the oil film does not immediately return. After a few moments of constant scoring, the piston and cylinder will scratch each other hard enough to remove material from each other. This floating material grinds itself into the piston and the cylinder as it continues to grow in size. As this snowballing material grows, it will drive the opposite side of the piston against the cylinder wall with a pressure so terrific that scoring begins to take place. While all this is going on, your engine is still running wonderfully at full throttle. The death blow comes when the mass of material between the piston and the cylinder wall finds it's way to the piston ring. This nearly molten mixture of aluminum and iron will instantly lock the ring in it's groove. This ring locking, not the piston surface seizure, is what actually causes your engine to quit. When the piston ring becomes locked back in it's groove, it's incapable of providing compression sealing against the cylinder wall. This instant loss of compression, while the engine is at speed, causes a dramatic loss of power. That power loss, along with the added drag of the badly seized piston, makes the engine quit or lock up in a nanosecond. In fact this entire seizure process, from the first scoring scratch to the piston locked solid, takes less than a second at full rpm. That's not even enough time for you to utter the first syllable of your favorite profanity. THERE ARE MANY CAUSES OR SOURCES OF PISTON SEIZURE. Each cause has it's own symptoms and it's own visual results. The following is a description of several very common types of seizures, and the most common problem source for each one. It should be understood that diagnosing piston seizures is not done with any precision by even the best engine builders. However this information may allow many of you to make a more educated and accurate guess. Four corner seizure: Both sides of the piston will show heavy scoring and seizure marks on each side of the wrist pin hole. The pattern of these four seizure points often appears to be a perfect square, hence the slang term "four corner". The scoring takes place in this pattern because those areas of the piston casting are the thickest. When the piston is seriously overheated, the thick areas will expand and distort the most. High output kart engines usually experience this type of seizure pattern when a piston has been fitted with too little clearance. Most experienced , and well meaning, kart mechanics would take one look and immediately say that insufficient piston clearance is the cause. However that diagnosis, on watercooled engines, would be wrong about 99% of the time. Four corner seizures in watercooled engines are almost always a result of the engine creating more heat than the cooling system can exchange away. That is not to say that most cooling systems are under built, but rather that it's easy to make a modification that creates too much internal heat for even the most beefed up cooling systems. Even though a constant feed of cool water is being moved through the cooling system, the cooling system must be capable of exchanging the engine heat away at a rate quicker than the engine is creating it. The engine factors that have the greatest seizure related effect are operating temperature, excessive compression ratio, ignition advance, high rpm, insufficient fuel octane level, insufficient cooling, or any combination of these. Properly adjusting these same factors will have the greatest effect on total power output. The job of the engine builder is to find the right combination, or "blend", of these factors that will result in strong overall power output at a pace that your cooling system can keep up with. There are many engine builders who have mastered their own combination "blend" that can get you all the power your after without risking a seizure. A group of mismatched modifications is a first class ticket to "seizure-land". Any inexperienced individual who sets up your engine with over 200 psi of compression and advanced timing, is also guaranteeing your arrival. If your big mouthed racing buddy down the street tells you that he can make any engine "roost".... You should think twice. You could be in for a very expensive lesson. Lean seizures: The high speed circuit on almost all kart engine carbs are responsible for delivering fuel in the 30%-100% throttle range. If the high speed circuit is lean enough to cause piston seizure, it will also tend to cause a laziness in mid-range throttle response. Dangerously lean high rpm racing motors can sometimes offer acceptable mid-range, however they will accelerate to peak speed very slowly. The classic lean seizure exhibits heavy scoring and seizure along the entire width of the exhaust port with only light scoring on the opposite piston faces. In lean mixture conditions, the exhaust gas temperatures escalate quickly into the meltdown stage. Those high temperature gases can compromise or completely burn off the oil film on the exhaust piston face as the exhaust port is being covered up. With the oil film weakened or gone, scoring quickly turns into seizure and ring locking. Air leak seizures: If you could pressure check every engine that showed up at a local racing event, you would find some of them to have an airleak. Because of the varying degree of these leaks, some will result in seizure, others will only cause poor carbureton or slight overheating. The varying effects of these air leaks makes this a difficult diagnosis. In any situation where an engine has seized for no apparent reason, the motor should be pressure tested before any other teardown work is performed. If a mechanic does not have the equipment to pressure test your seized engine, it's very unlikely that he will have the finesse to accurately diagnose your problem either. In fact, pressure testing should be a standard finishing procedure for any major engine reassembly work. Race engines should be pressure tested every re-build. The air leak piston seizure, depending on the severity of the leak, can look like a four corner type or a lean mixture type of scoring pattern. If an engine is operating on the ragged edge of overheating, a small air leak can easily cause the extra overheating that will result in a four corner seizure. On the other hand, a huge air leak will draw in so much additional air that even an over rich engine can experience a lean type seizure at full rpm's. Detonation seizures: If a modified engine has been prepared with too much compression or spark advance, or if it's run on unacceptably low octane fuel, it will begin to "ping" or detonate. Detonation is a big subject the merits another article of it's own. For now we only need to understand that it causes a terrific amount of internal heat in a very short time, as well as physical damage to the combustion chamber. If you have ever seen the outer diameter of a cylinder head dome that looks as if it's been eaten by termites, you have seen the results of detonation. It packs a physical force that is roughly equivalent to hitting the edge of the piston crown with a full arm swing of a ball peen hammer. In a short amount of time, this detonation pounding will collapse the ring land and lock the ring in place (usually on the hotter running exhaust side of the piston). As soon as the ring is locked, the flames of combustion burn the oil film off of the cylinder wall, and the scoring/ seizure process begins. Because of the exhaust side scoring and the swift overheating caused by detonation, you'll have a 50/50 chance of a four corner seizure or a "lean mixture" appearing seizure. Only an experienced engine builder will be able to accurately diagnose this seizure source. Cooling system seizures: This cause cuts into the gray area of piston seizure. A clogged cooling system on any machine can cause swift and serious temperature problems. However, no engine will ever experience a seizure purely as a result of inadequate cooling from the stock system. I have seen several karts run an entire trouble free season with a bone stock cooling system. These engines are not a statement of the effectiveness of the stock cooling system, but rather a statement to the benefits of having a professionally prepared high performance combination. The larger line and dual line cooling kits certainly have their merits on high output race engines that will be run at full throttle for extended periods of time. Their ability to more rapidly exchange away engine heat is a great asset on modified engines that are run at full throttle only. However, none of them can exchange away the excess heat created by a poorly prepared engine package. If you are experiencing chronic piston seizures of any kind, increased cooling may temporarily stave off the problem, however it will almost never cure it. Piston clearances As mentioned earlier, too little piston clearance is one of the most common " wrong " diagnoses made on seized watercooled engines. Most of today's engines come brand new with cylinder clearances that are .001"-.002" over the recommended factory setup clearance. This extra clearance is an added protection against drivers who don't follow the proper break-in procedure. If the clearance of a bored cylinder has been set at the factory recommended clearance, the close piston clearance by itself will not cause seizure. There is usually an added factor such as excessive compression or an air leak. If a piston if fitted with too little clearance, it will usually experience a four corner type seizure pattern. In most cases the ring will experience little or no damage. If this is the case, it's entirely safe to sand the score marks off the pistons and re-use them in the freshly honed cylinder. Too much piston clearance can also result in piston scoring and seizure. A piston ring, in an excessively large cylinder bore, will have a very wide end gap not to mention very weak ring tension against the cylinder wall. The flame of combustion can easily burn past this weak ring seal as well as down the end gap opening itself. If this flame burns off a significant amount of the oil film on the cylinder wall, the scoring seizure process begins. Break in seizures: The most common break in related seizure is usually caused by the ring not the piston. Some new piston rings come with a coating on their outer sealing surfaces. This coating seals to the cylinder wall in just a few operating minutes, which provides better power during the break in period. As the engine is breaking in, the Teflon eventually wears away and lets the hard surface of the ring come in from behind to provide the long term seal. The down side of this coating is that it makes for a dangerously small end gap during the first hours of operation. If the engine is run too hard too soon, the heat will cause the ring to expand in diameter which may drive the ring ends together and drive the ring surface hard against the cylinder wall. A piston ring that is being overheated in this fashion will easily have enough tension against the cylinder wall to scratch off the oil film which will begin the scoring/seizure process. A piston seized in this way will have heavy scoring around the entire diameter of the piston, with the ring usually locked into the groove all the way around as well. Lubrication related seizures By now it's apparent how important the oil film strength can be. Equally important is the amount of oil that is present in the engine. Most kart engines carry factory recommendations for oil premix ratios between 15:1 and 20:1. The total amount of time that it takes for a drop of oil to get from the carburetor, to the lower end bearings, to the top end, and out the exhaust port is called "oil migration time". As peak rpms increase, the amount of time that a drop of oil remains inside the engine is drastically shorter. In other words, a 17000 rpm race engine would need a mix ratio of about 20:1 to maintain the same internal lubrication presence that a 12000 rpm engine would have with a 30:1 mix. There are several oil brands that claim that their oil can provide equal lubrication at a leaner mix ratio (40:1 or 50:1) because of a claimed better lubrication quality. I have never experienced this to be true nor has any oil manufacturer, to my knowledge, proven it to be true. It's like running your truck on two quarts of a special oil instead of four quarts of a standard type oil. The quality cannot make up for the quantity.....Ever. Seizure by running out of gas: - as many people already know, a larger size needle and seat must often be installed into a carburetor to contend with the increased fuel demands of a moderately modified engine. If a modified engine is operated at full throttle with a stock size needle and seat, it will usually carry full rpm for about 2 or 3 seconds and then shut off as if someone hit the kill button. When the machine comes to a stop, the driver re-starts to see what the problem is. The engine, no longer in fuel deficit caused by the undersized needle and seat, unexpectedly starts right up. This instant high speed shut off is caused by the carburetor literally running out of gas. It is sometimes possible that during this shut down moment of fuel starvation, the engine is also starved of the oil that is pre-mixed in. This oil starvation may cause subsequent piston scoring or seizure. At the moment that the fuel starved engine shuts down, combustion and all the heat associated with it "ceases". A karts rear wheel traction continues to move the pistons in the bores at a very high "friction causing" speed,. This same concept applies to any machine that simply runs it's tank dry. It is possible for a driver, whose carb has an under sized needle and seat, to induce a piston seizure. However this would require a great deal of combined skill and stupidity. Once the driver has established that extended full throttle operation causes his engine to quit, he might make the very poor choice of only applying enough high speed throttle to avoid starving the engine. When he does this, he will be capable of maintaining about 90% throttle which will hold the engine endlessly on the lean thresh hold of fuel starvation. As this driver eventually masters this throttle position, he will be able to maintain a very high rpm with the carb feeding a horrificly lean mixture. Ultimately his finesse will be rewarded by one of the most abrupt and destructive lean mixture seizures that his mechanic has ever seen FABLES AND UNTRUTHS Cold seizure: - this is by far the most over used "seizure scape goat". It some how implies that the driver ran his engine in a way that caused the failure. At least 95% of the "so called" cold seized engines have had a very apparent problem elsewhere in the engine that the builder failed to see. Telling a customer that he cold seized the engine is an easy way for a mechanic to immediately reverse the guilt and the responsibility. If a freshly bored engine or a high performance engine were started from stone cold, and then run hard at high rpm within 30 seconds of the start up, it could very likely experience a true cold seizure. This happens because the aluminum piston would experience a radically faster rate of expansion in that 30 seconds than the cylinder does. The reason for this difference in expansion rate is two fold. First and foremost, the internal temperatures that the piston crown is exposed to at full load are on the order of 1500'C-2500'C. The gases passing through the exhaust manifold ports is also in this temperature range. The expansion rate caused by these temperatures is usually not a problem when the water entering the water jacket is preheated. During the first 30 operating seconds, cold incoming water will maintain the water jacket around the cylinder at "stone cold diameter" while the piston is becoming "full temperature diameter". On engines with properly sized pistons, the difference in these diameters becomes much more than even the best oils can withstand. Any engine that has been warmed up for 60 seconds or longer, would be virtually incapable of a "cold seizure" Hot water seizure: - the hottest water operated in high output race machines is about 92' C. Machines equipped with a single cooling line system show no signs of any piston scoring or seizure. There is evidence however that the warmer water causes engines to lose peak power ability during longer races. Leaning out: - this is a term for a phenomenon that doesn't really exist. It implies that a carburetor, whose needle/seat and high speed metering screw is properly set, will suddenly begin to meter slightly less fuel to the engine for no apparent reason. This does not happen .... Ever. In most cases what a driver is actually referring to is the way his machine begins to slow down noticeably during a long full throttle pass. In most cases this slowing is the result of a serious overheating problem caused by excessive compression, ignition advance or poor quality gasoline. __________________ Charlie 06 ktm300
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Turbinecore 2. USFS legal. Now I don't have to run like an outlaw when I see a apple green truck coming my direction! I'm impressed with the quality of this piece. The hangar is machined, not stamped. Fit-up was perfect, and the polished finish matches my nickel plated pipe. Looks much nicer than the stock silencer. It's about 3-inches shorter than stock and feels slightly lighter. Can't wait to see if it lives up to the performance claims!
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Some of the older guys swear that Maico was the best motocross bike ever produced. When they talk about them they get a far off look in their eyes you can almost imagine tears running down their cheeks as they reminisce. I’ve never heard the other side of Maico’s tragic demise. I was enthralled listening to this video. I hope you enjoy it and if you have a good Maico story please post it.
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Hey, does anyone know what these issues could be for my 2000 rm250? I’ve had the bike for 2 years now and it’s been a headache. I stopped working on it for 1 year and now I need some help. I replaced the throttle housing, cleaned the power valve assembly, fresh oil change, fresh mixed gas, new air filter, new reeds, spark is good, rebuild and cleaned the carburetor. On startup the bike rev's super high and doesn't seem to want to Idle down as shown in the video. The Idle and fuel/air screws are 2 turns out like factory recommendation. The clutch is also not working right, when I last worked on the bike over 1 year ago when it was able to stay running and ridable, the bike wanted to go after shifting into gear with the clutch still held in. Last, once again when I worked on the bike over 1 year ago, I was able to ghost ride it in every gear without it stalling and it doesn’t have a rekluse clutch, like I didn’t have to use the throttle to shift up or down without the bike stalling. Any other Ideas for fixing these issues?
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I would like to start a club for riders in my local area for a track that my dad is currently managing in the Rockymount/Greenville NC area. Any help is greatly appreciated.
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Paid a visit to my local dealership this morning. Talked about new Huskies and KTMs. I've had my eyes on the TC250 for a few years - almost bought one in 2020, but went with a YZ instead to use the difference in price to buy some new gear. In '21 the Husky won the shootout against the 250SX, with the TC's lowered chassis and some suspension upgrades that the SX didn't get. The '22s are basically unchanged from '21, but I'm told the '23s will have some new engineering, and they'll be taking dealer orders early this year- in April. Couldn't help myself... I put a deposit on a '23 TC250. Anyone here riding a '21 or '22 TC250? What are your impressions? What do you hate about them? What mods have you done?
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Hi All, I have TUbliss on my 350 and want to run a gummy REAR tire for single track/rocky conditions. Everything I read online states that double ply stiff sidewall tires are the best. Any one out there have a good recomendation that seats well with TUbliss and has a strong enough carcass to get the benefits of the system ? I have looked and most the threads are before the gummy tire boom or talk about tires that are not made anymore. If gummys stink for Tubliss and I should give up on that idea Im open to a wide harder compound suggestion. Please include size details (e.g. 110/100 18) There are sizes up to 140/80 now ?♂️. Thanks! Im currently on a IRC Gek V33s 110/100. Hooks up well but dosnt hold pressure (over night) as well as some other tires I have had and seems like its going to start loosing nobs just after 3 hours. Im OK with faster wear=performance but thats a weekend of riding for me.
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Question for Arizonans and southwest regional riders: If a new privately run moto park were opened in North East Arizona, (Sho Low area), would you make the drive to ride there? About four hours from Phoenix, five hours from Albuquerque, three and a half from Prescott, two hours from Flagstaff. Camping and RV hookups. This is AZ high country, 5,900' elevation. Summer day Temps in mid-80s, winters 50s. If I built it, would the riders and racers come? ???
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