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Know a little something about maintenance, fixing, tuning, or modifying MX, offroad, & dual sport motorcycles, ATV or UTV? Or, maybe you have mad skills riding or racing them? Whatever the case, if you have valuable knowledge & experiences that relates to motorcycles, ATVs, or UTVs, please help your fellow riders by sharing your best tips, tricks, and how to articles.
    Kevin from Wiseco
    Typically, riders will know when it’s time to freshen up the clutch in their dirt bike or ATV, if not by tracking maintenance intervals, then by experiencing problems with engagement and or an inconsistent feeling in the lever. These symptoms are commonly attributed to needing new clutch plates and fibers, but what can easily be overlooked is the clutch basket.
    When assembled, a clutch pack is stacked within the basket. The protrusions of the clutch fibers slide in between the “fingers” or “tangs” of the clutch basket. When the clutch is disengaged, the friction between the clutch fibers and the steel plates mated with the inner hub allow the power from the crankshaft to successfully be transferred through the clutch, to the input shaft, and eventually to the rear wheel. During this process, the clutch fibers apply force against the sides of the basket tangs. However, clutch basket tangs are not only responsible for this this axial transfer-of-power force, they are also subject to lateral force as the clutch pack moves outward and inward with clutch engagement and disengagement.

    Clutch basket "fingers" or "tangs" are responsible for withstanding both axial and lateral force during engine operation, causing wear over time on OEM parts.
    Due to these different forces applied to basket tangs, wear marks and notching can begin to form along the sides of the tangs. The severity of this wear will vary based on total run time, clutch use practice, and several other factors. Subtle, darker wear marks on are not necessarily of major concern, but once the marks turn to notching and can be physically felt with a pick or fingernail, potential for problems begins and the basket should be replaced soon to prevent getting to the point of breakage.

    Evidence of clutch basket notching.
    It’s worth it to note that this type of wear is most common for cast aluminum baskets, which are used in most Honda, Yamaha, Kawasaki, and Suzuki dirt bike and ATV models. Some late-era KTMs are equipped with steel baskets that are much more resistant to notching, but some KTM models still have aluminum baskets. Therefore, if your machine is equipped with an aluminum basket and you’re ready for a replacement, choosing an aftermarket replacement constructed of stronger material and more wear resistant features will ultimately give you the most hours for your buck over going with an OEM basket.
    Because Wiseco does all their own forging in-house, Wiseco’s clutch baskets are the only ones offered with forged construction instead of billet. Wiseco forges an aluminum puck into a bowl-like shape first, then does all the CNC finish machine work. This allows the grain flow of the alloy to align with the shape of the basket tangs, greatly increasing tensile strength. Topped off with a hard anodize treatment and Teflon coating, Wiseco clutch baskets are so wear resistant that they come with a lifetime warranty against notching and breakage. Plus, the coatings make for a very smooth pull in the lever.

    Check out all the details on Wiseco clutch baskets here.
    So, you’re ready to get rid of your old, worn clutch basket and fit a new one. With the basket out of the bike, this process consists of removing the starter gear, clutch-driven gear, dampers, backing plate, and screws/rivets from your old basket and fitting the two gears onto the new basket along with new dampers, fasteners, and a new backing plate.
    What’ll Help you Get the Job Done
    Hydraulic press or vice Center punch, drill/drill press and appropriately sized bits (or alternative equipment to remove rivets) Torque wrench Clutch Basket Replacement Process
    New Wiseco clutch baskets come with new rubber dampers, a new backing plate, fasteners treated with Loctite, and a hex bit to tighten the fasteners. Therefore, the only components you should be reusing when prepping your new clutch basket to go in the bike are the starter and drive gear.

    The starter gear and the drive gear are the two components you'll be re-using from your old basket.
    Step 1: Removing the Rivets
    There are several methods to removing rivets that are also dependent on the tools you have available. Our preferred method is a drill press to help ensure precise removal of the rivets without damaging either of the gears that need to be re-used.
    Before beginning drilling, punch a locating hole using a simple hammer and punch in the center of each rivet holding the backing plate to your old basket. This will help keep the drill bit guided in the center of the rivet when you begin drilling.
    Drill markings punched into rivet heads.
    Once all your locating holes are drilled, begin drilling out the rivets one at a time, drilling from the back side of the clutch basket. Be sure to choose a drill bit that is slightly smaller than the rivet so you don’t damage the fastener holes of the starter gear.

    Drilling out the rivets using a drill press.
    Step 2: Remove the Backing Plate and Starter Gear
    Once all the rivets are removed, the old backing plate and the starter gear can simply be lifted off your old basket. A small amount of hand force maybe required when removing the starter gear, as the rubber cushions are holding it in place.

    After removing the rivets, the backing plate, starter gear, and cushions can simply be lifted off.
    Step 3: Press out the Drive Gear
    The remaining gear still fitted in your old basket is the drive gear. This gear is pressed-in and held with an interference fit in the center of the basket with teeth on the gear that align with grooves in the basket. Our preferred method to removing this gear is with a hydraulic press. If you don’t have a press, a bench vice can typically be substituted.
    Whether you’re using a press or a vice, using proper fixturing and spacers to hold the basket in place and press out the gear is crucial to be sure you don’t damage the gear itself. Before you begin applying force, double check your fixturing and spacer sizing to ensure safe removal.
    Once you’re confident in your setup, simply apply force until the gear is free from the old basket. These gears are typically not exceptionally tight, so if you’re having trouble getting movement, double check that you’re pressing straight through and not accidentally applying lateral force.

    The drive gear can be pressed out fairly easily, but make sure to use fixturing and spacers that will not result in damaging the gear.
    Many applications will have a spacer that goes along with the drive gear. Be sure not to misplace that spacer, as you’ll need to reuse it.
    Step 4: Install the Drive Gear into your New Clutch Basket
    To install the drive gear into the new clutch basket, using a press or a vice can be avoided by using a combination of heat and chilling. Heat up your new clutch basket by setting it on a hot plate. Using a torch is also an option, but use caution as torches make it easy to apply too much heat. Heating up the basket causes the alloy to expand, making it easier to insert the new gear.
    While the basket is heating up, place your gear in a refrigerator or a freezer to chill it. This causes the material to contract, making it slightly smaller and easier to drop into the basket.

    Heating up the clutch basket on a hot plate and chilling the gear in a fridge or freezer aids in being able to drop the drive gear in the new basket without using a press.
    Once the basket is sufficiently heated (use proper gloves, it will be too hot to touch) and the gear is chilled, flip the basket over to the back side. Slide your spacer/washer (if applicable) onto your gear, then carefully align the teeth of the gear with the grooves of the basket, allowing it to drop into place. The gear should simply fall into place with no additional force needed. Once the basket and the gear return to normal temperatures, the material of each will return to normal properties and the gear will be interference fit and secured in the basket.

    With the proper temperature contrast, you should be able to drop the gear right in. Be careful, the basket will be hot. And don't forget the washer!
    Step 5: Install the Starter Gear, Cushions, and Backing Plate
    To install your existing starter gear on your new basket, begin by simply setting it on the back side of the basket in the same orientation in which you removed it from the old basket. Gears will vary by model, but most have a specific side that should be facing the basket.

    Next, install new, rubber cushions (included with the Wiseco clutch basket), aligning them within the openings of the starter gear and fitted around the stand-offs on the back of the clutch basket. These cushions are not symmetrical, so be sure to install in the same direction they were removed. Reference your owner’s manual if needed.

    Be sure all your cushions are inserted in the correct orientation.
    Once all the cushions are properly installed, place the new supplied retaining plate over the starter gear and cushions, aligning the holes with the threaded stand-offs of the basket, and secure it with Loctite-treated fasteners (new plate and fasteners also included with Wiseco basket). Tighten down the fasteners and torque them in a star pattern to ensure evenly distributed clamping force. Always reference your supplied basket installation instructions or your owner’s manual for the torque specification on the fasteners. Models that came equipped with a riveted basket will not have a torque spec supplied, so be sure to reference the installation instructions. Wiseco clutch baskets typically call for 80 in-lbs, but can vary depending on the application.
    Lay the new backing plate on top and tighten down with Loctite-treated fasteners. Torque all fasteners to the specification in your instructions or owner's manual.
    Once everything is secured and properly torqued, flip the basket over to access the inside of it and peen the ends of the fasteners. This process is simple; using a hammer and a punch, place the punch at the edge of the bottom of the fastener and aim it toward the edge of the threaded basket hole. Give it one firm strike with the hammer to push the material against the basket. This provides extra protection against the fastener backing out of the basket.
    Be sure to peen the new fasteners after torquing to spec. Strike a small indent at the edge of each fastener to reduce the risk of any of them backing out.
    And that’s it! After you’ve completed all the above steps, you’re ready to re-install the clutch basket in your engine via the process outlined in your owner’s manual.
    To enjoy the full package of protection and performance, Wiseco also offers forged inner hubs and pressure plates, as well as clutch pack kits, all working together to provide smooth, consistent, long-lasting clutch performance.

    Bryan II
    BREA, CA – November 19, 2020 – (Motor Sports NewsWire) – Executing a comprehensive plan to build a strong foundation for the future, Suzuki Motor of America, Inc. has announced it will restructure its operations in the United States. This new direction will reorganize the Suzuki Motorcycle/ATV and Marine Divisions into two separate companies set to begin operations on April 1, 2021. This new organization is designed to give both new companies the best opportunity to optimize their success in their respective industries.
    Suzuki Motor USA, LLC. will be headquartered in Brea, California, Suzuki’s corporate home in the United States since 1981. Suzuki Marine USA, LLC. will be based in Tampa, Florida in the heart of the marine business in North America. Suzuki first entered the United States in 1963 and was originally based in Santa Ana, California before moving to its landmark, Pagoda-inspired building in Santa Fe Springs, California.
    Satoshi Uchida will serve as Chairman and Masami Haga will serve as President of the new motorcycle/ATV company. Masahiro Yamamoto will serve as President of the new marine company. “
    The primary goal of this reorganization is to strengthen each business. Key objectives are to achieve greater efficiencies, speed up decision-making, and position each company for increased sales and growth in the United States.
    The location of Suzuki Marine USA, LLC. in Tampa was strategically chosen to expand Suzuki’s business, improve collaboration within the marine industry, and strengthen its relationship with boat builders, dealers, and vendors. The Gulf Coast location also provides convenient access to Suzuki’s new Marine Technical Center opened in Panama City, Florida in June, 2020.
    Source: Suzuki Motor of America, Inc.

    Kevin from Wiseco
    Piston ring technology has gone through a renaissance in the past 15 years. The age of the modern four-stroke ushered in the necessity for durable, highly powered machines. It only makes sense that piston rings were one of the first areas of interest. These days, powersports enthusiasts are blessed with an array of options built using space-age materials and coatings, unique geometries, and remarkable sealing technology.
    Here, we break down the newest advancements in four-stroke piston rings, and how these technologies can benefit engine builders and motorcycle riders alike.
    Three-Ring Piston Designs

    4-stroke pistons apply to a variety of different engine types in powersports, and many of them use 3-ring designs.
    Most four-stroke pistons use a three-piston ring design for effective compression sealing and oil control. The top ring serves as the compression seal. The uppermost ring’s job is to keep the combustion gases from getting past, effectively sealing the piston for maximum pressure. The second ring is responsible for catching any oil that may be on the cylinder wall. It helps scrape oil down to the third ring, which is a baffle ring that collects all of the oil. The bottom ring guides the oil through holes in the piston and down into the bottom end.
    “You don’t want the oil going up, just as you don’t want compression going down. You have to seal in both directions,” states Wiseco's engineering representative.

    The third ring is the oil ring assembly, which is made up of the baffle-style ring that collects oil, and two thinner rings that sandwich the baffle ring, and help keep it uniform in the ring groove.
    There’s also a very detailed geometrical design for every ring in a three-ring piston layout. The top ring typically has a gentle barrel face so that the ring contacts the cylinder wall in a very narrow path. This shape lessens the amount of friction, while still effectively sealing the compression. Conversely, the second ring has an angular face.

    The job of the top ring (lighter, machined color) is to seal compression, which is why it has a barrel-shaped edge face. 
    “Picture a jagged edge, where the sharp side is on the bottom. As it’s traveling downward along the cylinder wall it’s scraping oil, just like a windshield wiper as it’s going down,” mentions Wiseco's engineer.

    The second ring's job is to scrape oil as the piston travels downward. It has a jagged notch cut on the bottom of the ring to increase oil-scraping efficiency.
    Two-Ring Pistons
    Honda has long marched to the beat of a different drummer. It makes sense that the Japanese manufacturer wanted to go their own way when they introduced the CRF450R in 2002. The single-camshaft layout, known in marketing speak as “Unicam,” received most of the attention; however, Honda’s engineers also developed a unique two-ring piston design. By eliminating the middle ring in a traditional three-ring piston, the goal was to limit friction in the assembly and shorten the piston height. The latter benefit being a reduction in overall engine weight (the CRF450R was the lightest 450 four-stroke in its time).
    The top ring sealed compression and act as an oil scraping ring. The second ring collected the oil and sent it back into the bottom end. Honda was able to use a two-ring piston by developing technologies with the top ring that had, and continue to have, really unique geometries. Honda’s top ring seals compression and is also able to scrape oil on the down stroke. This was accomplished by putting positive twist on the piston ring.

    Two-ring designs in four-stroke pistons are still very relevant, mostly in racing applications, such as with the Wiseco Racer Elite pistons you see here. They allow for less friction and weight, but require advanced ring technology.
    Wiseco's engineer explains, “If the ring was sitting flat on a table, the outward edges of the ring would actually be upward. The ring isn’t technically flat, but instead cone shaped. As the piston heads upward toward compression, the ring is tilted upward and is sealing. When the compression event happens, the ring flattens out and seals solidly against the piston ring groove and cylinder wall.”  
    Once the piston travels downward, the lower ring starts to twist upward again, which brings the bottom edge of the ring out against the cylinder wall to scrape oil. The ring is effectively doing two jobs.

    Notice the bevel cut into the inner edge of the ring. This gives Wiseco rings positive twist geometry, meaning it can tilt and flatten inside the piston ring groove to accomplish compression sealing and oil scraping with one ring.
    Advancements in Materials
    Piston rings are not exempt from a continued focus on utilizing space-age materials for bolstering performance. Truth be told, rings were manufactured out of relatively simple materials 25 years ago. They were either built out of cast-iron or alloy steel with a moly- or chrome-faced channel where they contacted the cylinder wall. A lot of these new ring technologies are alloy steel, with a caveat. Rather than putting chrome faces on the ring, ring manufacturers actually harden the ring through a process called gas nitriding.
    “Gas nitriding is a process of introducing hydrogen to the surface, which hardens the steel,” notes Wiseco's engineer. “That makes the ring more durable, and results in better wear against the cylinder wall. The harder surface works extremely well against Nikasil cylinder bores.”

    Gas Nitriding rings hardens the material, increasing durability against today's extremely hard-surfaced Nikasil cylinder walls.
    Nickel silicon is an extremely hard surface. In order for the piston ring to properly seal against the cylinder wall, it, too, needs to have a very hard surface. The focus has been on making rings that are harder every year so they have better wear properties, and seal better against the cylinder wall.
    Low-Tension Technology
    Piston ring manufacturers have had to adapt to new-age cylinder designs, which have a tendency to distort. That’s due to motorcycle manufacturers constantly looking for ways to decrease engine weight. One way to do that is by casting the cylinders thinner and thinner. As a result, the cylinder doesn’t typically remain round or straight. This creates an issue where the piston ring becomes unseated. The solution is in using low tension rings. This technology allows the ring to conform to uneven surfaces. In essence, the ring is able to follow the undulations of the cylinder wall as it’s twisting and turning during the stroke of the piston.
    Ring Land Design
    Closely inspect the second ring land, which is below the top ring and above the oil ring. Notice a cut channel, which has a jagged shape that resembles a triangle. Flat on top and tapering off at the bottom, the unique shape helps assist in gathering oil as the piston is on the down stroke. This is called an accumulator groove. It acts like a piston ring that gathers oil and drives it down into the bottom end.

    One some pistons, you'll find a channel cut into the second ring land. This is not a ring groove. This is the accumulator groove, which collects oil and returns it to the bottom end.
    “Ring land design is extremely important in these new four-stroke engines that only use two piston rings,” states Wiseco's engineer. “You’re trying to take weight out and make things shorter and lighter. How do you do the work of three rings with only using two rings?”
    The answer can be found in the shape of the ring land. This scientific design helps control oil and makes sure that it doesn’t travel up past the piston and into combustion. Anyone that has a lot of hours on their piston and rings will be able to physically see that they have a problem when they fire their bike up in the morning and little puffs of blue smoke come out of the muffler. That’s due to the parts wearing out and oil getting into the combustion area of the engine.
    Lapped Rings
    Take a ride in the Mr. Peabody’s WABAC machine to the late 1990s, when automobile companies discovered that piston ring manufacturers couldn’t make a ring flat enough that was necessary for ultimate sealing. They relied on placing rings on a surface plate and grinding them down in order to remove any high points or imperfections to the surface. This process created a better seal against the ring groove. Known as lapping, the technology became popular in NASCAR and Pro Stock Drag Racing, where ultimate ring seal yields horsepower gains. The lapping process takes a production piston ring and turns it into something better. This technology is now available in the high-performance world of motorcycles.
    “Roughly a year ago, Wiseco introduced the Racer Elite piston kits. One of the features we have included is a lapped compression ring,” explains Wiseco's engineer. “It immediately provides better ring seal, so you don’t need any piston break-in period. Normally, the rings will need to seed themselves to the piston over time. We’ve eliminated that by having the ring lapped to the ring groove. It’s a very precise fit, and you get a really strong ring seal. In turn, horsepower is improved.”

    Lapped compression rings were a recent introduction to powersports with Wiseco's Racer Elite. It achieves ultra-flatness, creating a better ring seal, translating to more compression and more power.
    Wiseco was so impressed by the performance increase of lapped piston rings, they brought the technology in-house.
    Find out more about how well ring lapping technology improves performance.
    Wiseco's engineer states, “We have the capability to lap just about any piston ring to optimize the surface. We knew that we needed to do it all under our roof and sell it to the market. It’s interesting, because the Powersports market doesn’t know much about lapped piston rings. At the same time, it’s almost an everyday thing on the automotive side.”
    The benefits of a lapped ring are immediately noticeable. Performance gains, reduced blow-by, and the lack of break-in period put the Racer Elite piston kit front and center in the high-end, premium race parts category. 
    Gas Porting
    Gas Porting is a technique where tiny holes are drilled into the top of the piston that intersect the top of the ring groove. The technology forces combustion gases down through the holes and pushes the ring out against the cylinder wall. It’s a technique used to achieve ultimate ring seal, but it’s not meant for longevity. That’s because gas porting forces things to work against one another, resulting in the ring and piston to wear out faster. Gas porting is normally reserved for high-end applications, such as Drag Racing, because it bolsters performance (at the expense of a shortened lifespan).

    Gas ports are tiny holes that allow combustion gases in through the top of the piston and out inside the compression ring groove. This forces the ring out against the cylinder wall, improving the seal.
    Spider Tech
    Whether it's in the woods or on the motocross track, one of the critical components that have a significant effect on rideability and traction is your engine’s clutch. The clutch is responsible for transmitting power from the crankshaft to the final drive of your machine. Traditionally, powersports machines are offered with manual transmissions and use wet, dry, or slipper clutches.
    At Rekluse, we specialize in high-performance clutch solutions that are easily installable into engines traditionally utilizing wet clutches. Auto clutches have inherent advantages over the other clutch types mentioned. Before considering an auto clutch, it’s important to understand all the essential details of what an auto clutch is, how it works, and the numerous benefits that street and dirt riders can expect. Different auto clutch options are available depending on the type of riding and budget, so it’s important to understand which one is right for you.

    Auto clutches have inherent advantages, but it's important to understand all the critical details to know what's right for you. (RadiusCX cable actuated model configuration shown)
    What is an auto clutch?
    An auto clutch is a type of clutch that automatically engages and disengages the   based on engine RPM, and ultimately, the power being transmitted to the final drive. The ability to engage and disengage the clutch via rider input through actuation of the clutch lever is retained; however, rider modulation of the clutch isn't necessary in many situations.
    An auto clutch allows easy starting and stopping without using the clutch lever, and virtually eliminates engine stalling. Unless you have mastered clutchless shifting, the clutch lever is still used when shifting gears.

    Star Racing Yamaha has utilized Rekluse auto (RadiusCX) and manual (Core Manual TorqDrive) clutches throughout the 2019 and 2020 MX season. 

    Justin Barcia and the Monster Energy / Yamaha Factory Racing Team utilized the RadiusCX auto clutch for select rounds of the 2020 Lucas Oil Pro Motocross Championship. 

    Rekluse auto clutches automatically engage and disengage the clutch based on engine RPM. The option for rider modulation of the clutch via the lever is retained, but unnecessary, except for during shifting.
    An auto clutch should not be confused with an automatic transmission. Shifting gears is still an essential aspect of riding an auto clutch-equipped machine. An auto clutch is also different than a slipper clutch. When aboard a slipper clutch equipped machine and the throttle is chopped, the clutch disengages. When riding an auto clutch-equipped machine and the throttle is chopped, power transmission to the final drive is maintained, effectively maintaining engine braking.

    A unique characteristic of Rekluse auto clutches is their ability to retain engine braking when the throttle is chopped.
    How does an auto clutch work and what is an EXP disk?
    Centrifugal force is the governing force that allows an auto clutch to work. Centrifugal force is the resulting force that acts on an object rotating around a centerline. The heavier the rotating object or, the faster the object is spinning, the more inertia it will have, and the more force it will exert.

    An auto clutch features a special clutch disk that is designed to utilize the principle of centrifugal force. The Rekluse clutch disk that gives an auto clutch it’s automatic properties is called an EXP disk. The EXP disk essentially acts as a friction disk that responds to engine speed.

    The Rekluse EXP disk is the key ingredient to Rekluse's auto clutch formula. It's a friction disk built to respond to the centrifugal force of the spinning engine.
    The EXP disk is comprised of wedges that are positioned circumferentially around the clutch disk. The wedges are tuned and designed to respond to increases and decreases in engine speed. As engine speed increases, centrifugal force increases, and the wedges in the EXP disk exert an outward force on the two halves of the EXP disk, causing them to expand and the clutch to engage. As engine speed decreases, centrifugal force decreases, and the force exerted by the wedges decreases in the EXP disk, resulting in contraction of the two halves, which causes the clutch to disengage.

    To ensure the clutch is disengaged at idle, the clutch is set up so that a small gap of about 0.030” exists between the clutch pack and pressure plate. Off idle, as the throttle is applied and engine RPM increases, the EXP disk expands outwards, overcomes the installed gap, and engages the clutch. Since the auto clutch automatically engages at engine speeds higher than idle, the functionality of the clutch lever and traditional clutch deactivation/actuation methods can be retained without any modification. Finally, because an auto clutch works exactly like a standard clutch above idle, features associated with traditional clutch operation such as engine braking are also retained.

    Depending on your application and the auto clutch package you have, Rekluse has proprietary designs for adjusting installed gap, which is a critical step in optimum auto clutch performance.
    Advantages of an auto clutch
    If you’re considering switching to an auto clutch, here’s a few of the advantages and how they’re possible:
    No Stalling - Since the auto clutch engages and disengages as a function of engine speed and at idle the clutch is set up to be disengaged, stalling is not possible.
    Tunable - Rekluse EXP disks are tunable. The EXP disk can be tuned to engage at various engine speeds, and how quickly or “hard” the clutch engages can also be manipulated.

    Dead-on power delivery - An auto clutch simulates perfect clutch modulation which results in better traction.
    Reduces physical and mental fatigue - Since the utilization of an auto clutch yields fewer situations where the rider needs to engage the clutch, physical fatigue is reduced. Mental fatigue is also reduced since riders no longer need to focus as much on clutch operation.
    Clutch lever is still operational - If circumstances arise where manual clutch operation is advantageous, this can easily be accomplished.
    Engine braking is unchanged - Because an auto clutch operates just like a standard clutch above idle speed engine braking is not affected or altered.

    (RadiusCX DDS for KTM / Husqvarna hydraulic actuated model configuration shown)
    Who benefits from using an auto clutch?
    Rekluse auto clutches are designed for numerous applications and offer riders inherent advantages in each of them. There are application-specific advantages that riders can benefit from as well:
    - Automatic modulation of the clutch allows riders to ride a taller gear through corners.
    - The rear brake can be applied fully without fear of stalling.
    - Ease of operation allows the rider to focus more on their line.
    - Automatic modulation of the clutch allows for better traction in slippery conditions.
    - Navigation of technical terrain is easier.
    - Ease of operation allows the rider to focus on their line.

    "In the slicker, rockier, rooty-er stuff, I trust RadiusCX [auto clutch] more than my finger." -Ryan Sipes (Photo: Future7Media)
    - Navigation of technical terrain is easier.
    - Automatic modulation of the clutch allows for better traction in slippery conditions.
    - Steep and technical hills can be navigated without worrying about feathering the clutch to keep the RPMs up and the bike running.

    Zach Bell and the Precision Concepts team races WORCS and other West Coast GPs aboard their RadiusCX equipped KX450s.

    Rekluse RadiusCX Auto Clutch for the Kawasaki KX450
    Adventure Bikes
    The RadiusX auto clutch covers a wide range of Adventure Bike applications:

    Photo: Gnarly Routes
    Yamaha YXZ1000
     The Rekluse EXP 3.0 auto clutch for the Yamaha YXZ1000 allows you to operate the manual transmission with ease, with smoother clutch engagement which comes in handy when maneuvering at low speeds in technical terrain.

     Photo Credit: UTV Action, Cain Smead
    Auto clutch durability
    Similar to OEM applications, auto clutch durability depends on the end user and how aggressively they operate their machine. That said, Rekluse auto clutches are designed to last at least as long as OEM clutch applications. Since the clutch is mechanically engaged at the same RPM every time, clutch wear is consistent which helps prolong clutch life. Auto clutch durability also depends on ensuring the clutch is within spec and adjusted correctly. Auto clutch riders need to perform a simple and quick check called “free play gain,” which is a comparative measurement taken at the clutch lever periodically. 
    Why are auto clutches innovative?
    Rekluse auto clutches are innovative because there are no other clutch solutions on the market that offer significant rider advantages while at the same time retain conventional clutch functionality and ease of use. Innovation doesn’t stop at functionality, the number of installation options and the ease at which an auto clutch can be installed are also worthy attributes, not to mention the fact that no modifications are required to install any of Rekluse’s auto clutches.

    All Rekluse auto clutch systems are drop-in, no additional modifications are required.
    Auto clutch options
     To help you understand how each clutch option differs, the highlights of each clutch are identified below, and a comparison table is presented that also shows key differences. Whether you’re a top-level racer, avid adventure rider, or dedicated trail enthusiast, there is an auto clutch option for you.
    RadiusCX: $1,049 - $1,179 (Dirt Bike and ATV)
    - Premier, top of the line auto clutch.
    - Features all the latest technology offered: EXP, Core, and TorqDrive
    - Increased friction disk count transfers more power to the rear wheel while eliminating clutch fade.
    - Provides optimal lever feel.
    - Yields highest level of durability.
    - Increased oil circulation through the clutch.

    (RadiusCX cable actuated model configuration shown)
    RadiusX: $649 - $749 (Dirt Bike, ATV, ADV, Street)
    - Excellent mix of performance and cost – uses OEM hub and pressure plate.
    - Includes TorqDrive and EXP technologies

    Core EXP 3.0: $949 - $1,079 (Dirt Bike, ATV, YXZ1000)
    - Core EXP 3.0 uses OEM friction disks, meaning power transfer will be equivalent to stock engine performance.
    - Includes EXP and Core technologies.
    - Increased oil circulation through the clutch.

    Understanding how Rekluse auto clutches work is proof they are an advantageous option over various applications. View Rekluse clutch options for your machine here on the website, or use the dealer locater to find your closest Rekluse dealer. If you have any questions at all regarding which clutch is right for you, installation, or adjustment, Rekluse experts are happy to help and can be contacted at 208-426-0659 or by email at customerservice@rekluse.com.
    What the pros are saying:
    Rekluse and Star Racing Yamaha – Clutch Technology for Champions
    Dylan Ferrandis on Rekluse RadiusCX Auto Clutch
    Precision Concepts Kawasaki Team Manager Robby Bell on Rekluse
    Still not sure which clutch is right for you? Check out our complete guide here to help you decide!
    STUART, FL – August 31, 2020 – (Motor Sports NewsWire) –  Nihilo Concepts is known for being innovative and developing aftermarket parts for motocross and Off Road motorcycles. Their newest offering is the SOS Switch that will never leave you stranded.
    SOS stands for “Secondary On Switch” and that’s exactly what it is, a second starter button for your electric start Off Road and Motocross bike that will get you out of a pinch if you find your OEM switch won’t work.
    The new crop of Motocross and Off Road machines are all equipped with electric start, pioneered by KTM and perfected over the years the concept of an electric start has become a must have for most riders. Once you’ve pushed the button, you don’t go back to the kick starter. Because the systems are so good on the new bikes the use of a conventional kick starter has become obsolete so the manufactures have removed them to save weight. This is a big improvement to modern bikes, but what they failed to think about is they only left you with one way to start your bike. If your handlebar start button gets torn off the bars by a branch or other bike on the track, you would be left with no way to start your bike. Sure, you can try to push start it, but that’s not always possible. If you’re on dirt with no traction, the rear wheel will just lock up and slide leaving you panting and frustrated.

    The Nihilo Concepts SOS is designed to eliminate this problem by providing a waterproof, durable, Military Grade, easy to install, auxiliary start button that you install in a safe tucked away location, so if you crash or tip over and damage the OEM button, you will have a second safe and protected button ready to go. The SOS is light and small, so there is no concern about adding weight or bulky accessories. It comes with everything you need and installs easily between the handlebar button and the battery in just a few minutes. The Nihilo Concepts SOS will give you peace of mind and security knowing that if you are miles away from your truck on a winding trail or in the back corner of the motocross track and your stock start button fails you won’t be pushing your bike back to the truck, you will simply reach for your SOS and be back in action.

    The Nihilo web site provides videos and complete instructions for every brand so you can see exactly how to install the SOS on your bike if you have trouble just give them a call at 866-4-NIHILO and they will walk you through it.

    The Nihilo SOS is the accessory that you didn’t even know you needed, but if you ever find yourself stranded, you will be glad you picked one up. Go to www.nihiloconepts.com today to see the full line of innovative products for your dirt bike.
    MSRP $69.99
    Source: Nihilo Concepts

    With years of performance piston experience, JE knows ring operation is just as important as piston quality. Follow along with our complete guide to installing rings on your motorcycle piston(s).
    The correct installation of the piston rings is an essential aspect of rebuilding any four-stroke engine. This task is perceived by many to be simple. However, there are vital aspects of ring installation that should not be overlooked. Improper installation of the piston rings can result in limited engine life, reduced power, and high oil consumption. In this article, we’ll walk step-by-step through the ring installation process so that the next time you’re rebuilding your engine, you know exactly what to do and what to watch out for.

    JE now has pistons available for many late model applications. Find the performance you've been looking for.
    For starters, never attempt ring installation without the appropriate documentation available for reference. At JE Pistons, comprehensive instructions are included with most new piston kits. This ensures the engine builder has the necessary information available to do the job successfully. The machine’s factory service manual should also be on hand throughout the build so that things like torque specs, service limits, and procedures can be referenced.

    It's important to read and understand any assembly and installation instructions that come with your pistons.
    These instructions are for representational purposes only and not valid for all JE pistons.
    Process Overview
    Before diving into installation details, a quick recap of the process will be helpful to understand what’s to come. Shown below is an outline of the major steps you’ll go through.
    Measure ring end gap Clean all rings Mark piston where the end gaps should align Install oil rings Install 2nd compression ring Install primary compression ring Verify groove clearance Not sure which piston ring set you need to order? Check out our guide here.

    In addition to understanding the steps you'll be performing, laying out all the components needed helps stay organized and prepared.
    Time for a new piston kit? Find one here!
    Step-by-step Process
    Measure Ring End Gap
    Before installing the rings onto the piston, it is imperative that the ring end gaps are checked and verified against the specs provided with the installation instructions or factory service manual, whichever is applicable. If more than one compression ring is used, confirm any design differences between the two by referencing the installation instructions. Chamfers on the inside edge of the ring or different markings at the ring ends are common identifiers used to denote ring differences. Need clarification on all the markings used on JE rings and pistons? Click here.
    To check the ring end gap, simply install the appropriate ring into the cylinder bore and position it near the top of the bore. Use the depth rod end of a caliper to ensure the ring is square to the bore. Next, use feeler gauges to measure the ring’s end gap. Carefully insert various thickness feeler gauges between the ring ends until the gauge just begins to drag between the ring ends. Note the thickness of the gauge and compare it to the end gap specifications provided. This process can be repeated for any additional compression rings used.

    The majority of JE's motorcycle rings are pre-gapped, but it's always good practice to check ring end gap for all compression rings prior to installing on the piston.
    At JE Pistons, the ring end gaps are preset at the factory to fall within spec when installed in healthy cylinders used for normal applications. The end gap of the first compression ring should always be less than that of the second compression ring. If the end gap specs are outside of range, first double check your measurements and verify the cylinder bore is the correct diameter. Assuming no issues are found with the measurements or cylinder bore and the end gap measured is too tight, the rings can be carefully filed. To do so, use a small file and file one end of the ring. Be sure to maintain parallelism to the other ring end as you remove material. Remove small amounts of material and check the end gap periodically so that you don’t remove too much material.

    If ring end gap does need to be adjusted, evenly file one end of the ring only in small increments and continue to check until it's at the desired spec.
    All piston rings should be cleaned before being assembled onto the piston. Before cleaning, confirm the ring ends are free of burrs. Any burrs present can carefully be dressed by gently breaking the edge with a small file. Next, use your preferred parts cleaner to wipe down the rings and piston.

    Make sure your rings are clean and free of any debris or burrs.
    Mark the Piston
    Review the instructions provided with your piston kit, or the guidelines provided in your owners manual if no alternate instructions are provided, and note the specified positions of the ring end gaps. Use a marker to mark the edge of the piston crown with the intended ring end positions for the oil control and compression rings. Doing so will help ensure no orientation mistakes are made upon ring installation.

    Follow the ring end gap orientation instructions for your specific piston(s) and mark the piston so you know where each end gap should end up.
    Oil Control Ring Installation
    Modern oil control rings typically utilize a three-piece design and consist of two side rails and an expander ring. Three-piece oil rings can be challenging to install if the ring design and methodology are not understood. The expander ring is the waffle shaped ring and features a stepped edge on the top and bottom of the ring. The side rails are the two small, thin rings which complement the expander. When properly installed, the side rails sit on the top and bottom of the expander ring against its stepped edges. For this reason, the expander ring must be installed first.
    The other feature of the expander ring worth paying attention to is its ends. Due to the expander’s accordion-like shape, it is possible for the ring ends to overlap in the ring groove. For proper installation, it is imperative that the expander’s ends butt and do not overlap.

    The ends of the expander ring should be touching, but not overlapping.
    To install the expander ring, lightly coat it with engine oil. The expander ring is non-directional, so it can be installed in any orientation. Carefully work the ring past the compression ring groove into the oil ring groove. Adjust the expander ring as necessary, so the ring ends are correctly positioned. Ensure the ring ends butt together and don’t overlap.
    Start by installing the expander ring after lightly coating with oil.
    The side rails are also non-directional. Lightly lube the side rails then install them on the piston. Make sure the side rails sit correctly against the stepped edge of the expander ring and that their end gaps are positioned properly. Once the side rails have been installed, double-check the end gap positions of all three rings that comprise the oil control ring assembly.  Ensure the expander ring’s ends are not overlapped and ensure the assembly moves freely within the oil ring groove.
    Oil and install the oil expander rails below and above the expander. Be sure they are resting evenly and the end gaps are lined up with the appropriate markings.
    Compression Ring Installation
    If the piston utilizes two compression rings, the second compression ring should be installed first. Refer to the installation instructions to determine the proper orientation of the ring before installation. Typically, dots or letters will be marked near the ring end, which denotes the top of the ring. Internal edge features such as chamfers may also be used to identify the ring and its correct orientation. Lightly oil the ring and then carefully work it over the piston into its appropriate groove. Adjust the ring’s end gap position so that it aligns with the mark you made for it on the piston crown. Repeat this process for any remaining compression rings.

    Install the compression ring(s) in a similar fashion, lightly applying oil and carefully working the ring around the crown of the piston. Be careful not to twist or bend the ring out of shape as it could affect its ability to seal properly.
    Confirm Groove Clearance
    Once the compression rings have been installed, the ring-to-groove clearance should be checked. To do so, insert a feeler gauge between the ring and groove. The clearance can be identified by finding the feeler gauge that drags ever so slightly between the ring and groove. Note the groove clearance and compare it to the specification provided in the installation instructions or factory service manual.

    One of the final measurements to take after the rings have been installed is compression ring to groove clearance. Use a feeler gauge for this and find the size that has slight drag. Compare this spec to what's outlined in your instructions or owner's manual.
    At this point, ring installation onto the piston is complete, and subsequent steps can be taken to complete the engine build. While installing the piston rings onto the piston is a critical step in the build process, it can be performed by anyone when the proper steps are taken. The process simply requires the correct measurements are taken, cleanliness is ensured, and installation techniques are used.
    In search of a quality, performance forged piston for your bike? Click here to see what's available for your machine.

    Tired of your ride and want to try something new? Bike too big or too small and think you need a size adjustment? Here are a few pointers on how to trade what you have now for that perfect bike you’ve been dreaming of at little to no cost! If you are thinking of swapping dirt bikes there are a few strategies that you must be familiar with to be successful.  
    The first strategy and the hardest part of trading off road motorcycles is getting one in the first place if you do not already have one. Riders do like to swap bikes, however it is uncommon that they want to trade it for something other than another dirt bike. The only people who are usually looking to get out of the sport are those that either have been injured or those who have a new family and no longer have the time to ride. In either case both those types of people are usually looking to maximize their profits to help out with their respective causes.
    If you do not already have a bike I found that there are two main items people usually swap one for. The first are ATV’s. People who have dirt bikes tend to be hooked to off road riding, though some find dirt bikes too hard to too risky. These are the types of people that want to swap for an ATV. It’s been my experience that most people prefer 4X4 ATV’s instead of the race ATV. I find this I mostly due to again race ATVs being too fast and higher risk. Also some people prefer them because you can have a passenger and is cheaper to ride 2 up on an ATV then have 2 bikes. If you don’t have an ATV to trade the second most popular trade item sought are boats. The most popular boats accepted as trades seem to be bow riders. After contacting a few of these people, it seems that they no longer have the time for both their fishing and biking past times and they chose fishing as their primary activity. Lastly if you have neither an ATV nor boat to trade you can try household items such as riding lawn mowers, snow blowers, hunting equipment etc. I was able to secure a 1984 Honda CR 125 by trading some camping equipment I had just sitting in my basement. I did have to drive over 6 hours but seeing as how I was looking for trades for a few months at that point I jumped at the chance.

    The second strategy of trading is if you have a two stroke then trade it for a four stroke or vice versa. We all know the two vs four stroke debate. Some people just prefer to ride the one style vs another. This is your opportunity to profit by finding someone who just rode their buddy’s horse from a different pasture and trading with them. Nobody likes to lose out in a deal but you can turn that feeling of joy they felt in riding the other style bike into value in your bike. What I mean is people will trade their newer bikes for ones a few years older simply because they feel that style is better for them. This may take some convincing by reminding them how great that snappy responsive two stroke is vs their heavy slow four stroke, or how much smoother and more neighbor friendly your four stroke is vs their two stroke. The main point here is find out why are coveting their neighbor’s goods and play on that. Most of the time people are willing to sacrifice to trade for your bike that’s a few model years older to get what they want.

    The third way to trade up bikes is to trade one in perfect running condition for one that is not. The purpose for this would be to trade from an older model of either stroke to a newer one. For this you will need some mechanical prowess and a few dollars depending on what needs to be done. I wouldn’t really recommend trading a fully functional bike for a nonfunctioning one unless the nonfunctioning one is significantly newer. One of the main points here is that the newer bike should have a greater value when running then your old bike plus the amount of money you’re going to sink into the new one to get it running. This is how I was able to get from my 1984 Honda CR125 to a 2005 Yamaha 250F. The owner could not start it and just wanted a bike that ran. As it turns out all the bike needed was a valve shim (At this point in my riding career I was just starting to work on bikes and made a fatal error in placing the new shim causing a catastrophic failure but none the less the bike was able to start and run. Had I done the work correctly I would have been well ahead but more on this in a later blog) Beware of people who claim it just needs a carb clean, as this is almost never the reason it’s not running. Be prepared to replace the whole valve train.
    Another way of trading and the fourth on this list is trading from a motocross style bike to a trail riding model or vice versa. Often times a racer will want to give up on the motocross scene and get into the relaxed world of trail riding. This may be your opportunity to trade your slightly older comfortable Cadillac cruising trail bike for their newer high revving beast. On the contrary others may opt to want to get into the fast paced world of mx racing and give up their newer modded trail riding pony for your motocross bike. I personally traded my 2005 Yamaha 250F for a 2004 Yamaha WR250F for the reasons stated above. The race bike was all I could trade for at the time, but it gave me leverage to get into the WR. A fellow in my town build a new mx track so I was able to capitalize on someone trading in their trail bike to get onto the track. Most people are wary to get a bike that has been raced, but if you’ve taken care of it, have a log of the work that’s been done and can show receipts of work you will have a much easier time. I tend to trust racers who know their bikes inside and out more than I do the backyard trail riders who have never checked their shims or cleaned their oil screen. There are however some racers who bag the crap out of their bikes then dump them, and trail riders who meticulously care for their princesses so you have to ask the questions. What have you done, when and how many hours.

    Lastly the fifth method of trading is for power. There are plenty of people out there who bite off more than they can chew and are looking to trade their 450 four stroke or 250 two stroke for the next smaller size down. This also works in reverse for people who have outgrown their bikes and are looking to trade up. Many times they are willing to sacrifice a couple of model years to achieve this, or go from a more expensive brand to a less expensive brand to get what they want.

    Some other points when it comes to trading are to be patient. Frequent all of the different online used sites. Some people include a willingness to trade in their ad, others don’t, I would ask everyone who has an online ad regardless on if they say they will trade or not as often times they have just never thought of it. Never trust anyone at their word on what the bike needs to be repaired unless it’s backed up by a repair shops written opinion. Be willing to travel and check your neighboring town’s ads as well. Its rare, but you may also benefit by trading your bike for something not necessarily what you wanted, but something that is more trade-able or more desirable then what you have as a mid-step to trade for what you want.
    Do you have a good trade story? Share it in the comments below!

    Paul Olesen
    There’s nothing more alarming than realizing your four-stroke powered pride and joy is burning and consuming abnormal amounts of oil. Whether it’s a first-hand account or lending a sympathetic ear to a buddy dealing with the problem, we’ve all been there to some degree. I recently had a customer detail his machine’s oil consumption problems and logically explained away all the possible reasons why the engine could be burning oil. He had always changed his filter routinely and oiled it properly, he changed his oil every 10hrs, and he always kept up with his maintenance. So what the heck causes our four-stroke engines to consume oil and how do we figure out what we’re dealing with on a case by case basis?
    Points of entry
    The power cylinder of a four-stroke engine isn’t all that complicated. We have intake and exhaust valves in the cylinder head, and we have a piston assembly that features compression rings and an oil control ring. Knowing this oil can only migrate into the combustion chamber one of two ways, either past the valves or past the oil control ring.   
    Causation is another story, and the list of possibilities is a bit longer and depends on the unique circumstances of the situation. Contributing factors can range from the person who performed work on the engine, to the environment (dusty conditions and type of dust), to the general design of the engine. Here’s a list of some common causes which ultimately lead to engines that inevitably consume oil:
    Improper air filter maintenance - Your engine’s air filter is the primary device that separates out the dirt from the air and ensures your engine consumes highly filtered air. Filters that are improperly oiled or maintained will compromise your engine, especially if you are operating in dirty, dusty environments. Even the tiniest of dirt particles that breach your filter can have quick and adverse effects on the durability of your engine. Dirt ingestion will lead to accelerated wear of piston rings and valves, ultimately driving an increase in oil consumption. The oil control rings and cylinder bore become compromised when the dirt is ingested into the engine.

    Poor air filter seal - An air filter that does not fully seal to the airbox provides an unfiltered leak path for dirt saturated air to make its way into the engine leading to the previously mentioned durability problems. A leaking or poor sealing intake system - From filter to the engine’s intake manifold, all the joints and connections must be airtight. An improperly seated throttle body, for example, will allow dirt ingestion to occur.  Bad maintenance habits - Any time you open up an engine, you create a rich opportunity for self-inflicted dirt ingestion. For example, swapping out a dirty air filter for a clean one without first cleaning the entirety of the airbox is a common way engines become saturated with dirt. Our machines are tightly packaged, and it’s incredibly easy to rub your hand against a dirty component, causing dirt to fall into the intake tract or engine itself if performing more extensive maintenance.

    Improper assembly of engine components - For a select few, installing parts such as oil control rings incorrectly can be the reason the engine consumes oil. Similarly, valve stem seals can be installed wrong or more frequently be damaged during a hasty installation. On some engines, where the engine and transmission oil are separate, directional crank seals can be installed backward, leading to migration issues from one cavity to another.  Infrequent oil changes - An engine’s oil has a threshold for the amount of dirt and other contaminants it can suspend before accelerated wear occurs. Operating an engine for too long without changing its oil significantly increases the likelihood of the oil becoming an abrasive slurry causing its internals to wear out.

    Unrealistic expectations - High-performance four-stroke engines have a finite life to them before they require a rebuild. The amount of life any engine has depends on numerous factors, including how it is maintained, what it is used for, and the environment it’s operated in, to name a few. If you have a high time engine that is starting to consume oil, consider being grateful for the trouble-free hours you’ve gotten out of it and take on the rebuild to return it to its trouble-free days. Bad rebuilds - Uneducated builders can cause their own problems by attempting to cut corners during their overhauls. A common way to do this is by installing new piston rings to a worn-out cylinder bore. A worn cylinder bore can make proper ring sealing impossible due to both inadequate cross-hatch and out of tolerances in bore taper and roundness. Diagnostics
    There are a handful of ways to try and pinpoint where problems are originating. No method is entirely foolproof, and a bit of judgment is always required when making determinations. Here are a handful of diagnostic options you have at your disposal:
    Leak down testing - Leak down testing permits a quantifiable way to determine how well the cylinder is sealing and, if it is not, where leaks are originating. When diagnosing oil consumption problems leak down testing can overlook a faulty oil control ring if the compression rings are still sealing well.

    Compression testing - Performing a compression test is one of my least favorite ways of diagnosing four-stroke problems, but I am mentioning it because it can be used in a pinch. The main problem with compression tests stems from the incorporation of decompression systems, which significantly reduce peak pressure readings. Oil sampling - having your engine oil sampled by a lab can provide a great deal of information in regards to what is going on in your engine. For example, an oil sample containing high amounts of silicon is indicative of dirt ingestion. An excess amount of other elements can also suggest ring or bearing wear. Bore Scope - Checking the cylinder bore’s condition by using a borescope can be an excellent way to evaluate the health of the bore. Visible scuffing or deep scratches can be paths oil can sneak past the rings and into the combustion chamber. Closing Remarks
    I hope you’ve enjoyed this write-up on contributing factors leading to oil consumption and how to pinpoint them. While the problem is no doubt frustrating, there is no reason it has to be a reoccurring one, nor should you have to stew for days trying to determine the root issue. If you’re interested in more engine building knowledge, check out my Engine Building Handbooks, which arm you with a comprehensive knowledge base for overhauling your two and four-stroke engines. The Four Stroke Engine Building Handbook contains over 300 pages of highly detailed practical knowledge and over 250 high-quality color pictures. The books’ consistent five-star reviews on Amazon are a testament to how beneficial they are to our customers. To learn more, you can check them out on our website or on Amazon.  

    Paul Olesen is an powertrain engineer, author & long-time rider living in Wisconsin.

    We know this is technically 'Thumper'Talk, but we also know a lot of you have 2-strokes in your garage. We want to share some tips we put together that will help you prevent and diagnose potential problems with your 2-stroke engine. Bookmark this maintenance guide to help keep your bike on the track or trail and off the bench! Article by Paul Olesen.
    Two-stroke engines have a storied history of being finicky beasts. If you’ve been around two-strokes for any length of time, you’ve probably heard stories that start and end to this effect: “It was running amazing...then the next thing you know - it blew”. We find these stories interesting, and empathize with the unfortunate owners or riders who tell them. At the same time, however, it is often wondered if there were any signs that could have predicted the fateful date with destruction.

    Photo: Steve Cox
    We're going to discuss and share a number of observations and diagnostic tests that can be performed to help identify whether or not your engine is going to leave you in the unfortunate role of the broken engine storyteller. While many operators are insistent that their engine gave up without warning, this is often not the case. We’ll start by going over observations that can be made with the engine running, and progress into diagnostic tests that can be routinely made to assess engine health.
    Recognizing Symptoms
    Does the engine struggle to start when kicked, but is more prone to coming to life when the electric start is used or when the machine is bump started? Poor starting under normal conditions is not an inclusive sign that the engine is doomed to a spectacular failure, but it is a sign that something is amiss. Carburetion or injection issues are possible, but the bigger potential issue to be aware of resides within the cylinder. 

    Worn piston rings can cause incomplete sealing, resulting in lower compression and more difficulty in starting.
    Worn piston rings or reed valves that are no longer sealing properly may be the cause of the poor startability characteristic. When the piston rings don’t seal properly, the engine doesn’t build good compression, so when kicked, the engine struggles to come to life. Similarly, if the reed petals are damaged or broken, less air will be trapped in the cylinder. Push the machine or use electric start, and the compression event is shortened via faster rotational speeds, which may be just enough to bring the engine to life. 
    Damaged or worn out reed petals will allow air to leak out, creating less cylinder pressure and starting/running difficulties.
    Inconsistent Performance
    Does the engine struggle to hold a tune, or seem like the jetting constantly needs attention, despite relatively stable atmospheric conditions? Sporadic running is not always a death sentence, but should be investigated further. A dirty carburetor or worn spark plug can contribute to this behavior, but the problems that can lead to catastrophe are worn engine seals or gaskets. Stator side crank seals, leaking base gaskets, or intake manifold gaskets are all examples of seals that will result in air leaks which can lean out the air fuel ratio. Lean air/fuel ratios when running at full power can result in excessive combustion temperatures, which can melt a hole in the piston or seize them in the cylinder bore.

    Ignoring the possibility of a bad gasket or seal isn't worth the potential damage, especially with the affordability of OEM quality gasket kits from ProX.
    Gearbox Oil Consumption
    Loss of gearbox oil is abnormal, and in all cases should be able to be traced back to leaking seals or gaskets. In the unlikely event the bike tipped over or cartwheeled, gearbox oil can occasionally exit via the gearbox/crankcase breather. If the gearbox is losing oil but the leak path cannot be identified externally, there is a good chance the drive side crankshaft seal is leaking and allowing the gearbox oil to migrate into the crankcase. During the scavenging process the oil is transferred up into the combustion chamber and burned.
    Tracking down a leak like this and finding you need new crankshaft seals will commonly turn into a bottom end rebuild job. If you're going to tear into the bottom end to replace seals, that same amount of wear the seal experienced could be evident in other components as well, including your crankshaft and bearings. Not only does ProX make it easier to tackle a bottom end rebuild with our rebuild guide (10 Tips for a Dirt Bike Bottom End Rebuild), but one of the most recent additions to the OEM-quality replacements parts lineup are complete crankshafts. Dropping in a complete ProX crankshaft paired with a main bearing and seal kit is an affordable option for reliable performance.
    ProX crankshafts are assembled with double-forged, Japanese steel connecting rods, as well as Japanese big-end bearings, crank pins, and thrust washers, all manufactured by OEM suppliers.
    Excessive Smoke After Warm Up
    Since the engine is burning pre-mix oil we have to be careful here, because blueish-white smoke is a normal occurrence of two-stroke engine operation. However, excessive smoke after warm up can be an indicator of a couple problems.
    Blue smoke exiting the exhaust pipe after the engine has warmed may be a sign that gearbox oil is burning in the combustion chamber. While I would never encouraging sniffing your exhaust, combusted gearbox oil will have a different odor than the normal pre-mix oil the engine is using. White smoke exiting the exhaust pipe after the engine has warmed may be a sign that coolant is burning in the combustion chamber. The root of this problem is typically a leaking cylinder head gasket or o-rings. Excessive Coolant Exiting the Overflow Tube
    While it is common for coolant to exit the overflow tube when the bike has been tipped over or when it has overheated, it should not occur regularly. Coolant blowing out the overflow tube is another good indicator of a leaking head gasket.

    Note where your coolant overflow line runs, so you can keep an eye out for overheating issues.
    Coolant Weepage
    Dribbles of coolant exiting the engine around the coolant pump are indicative of a faulty water pump seal. If left unattended, the entire cooling system will eventually empty, causing overheating and an incredible amount of damage.
    Excessive Top End Noise
    Isolating top end noise in a two-stroke is easy since the only moving component is the piston assembly. Discerning what is normal takes a trained ear and familiarity with the particular engine in question. However, audible cues often present themselves when components wear or clearances loosen up. The most common noise associated with a two-stroke top end is a “metallic slap”. This is commonly referred to as piston slap, and is a result of the piston rocking back and forth in the cylinder bore as it reciprocates. This phenomena is normal, but the intensity of the slap will increase as the piston skirt and cylinder bore wear. Left unattended, excessive piston slap can result in failure of the piston skirt.
    Check out our complete 2-stroke top end rebuild guide here.
    Excessive piston slap can cause damage to the piston and weaken the skirts. It's important to check piston-to-wall clearance when installing a new piston to ensure a long operating life. 2-Stroke pistons fitted with skirt coatings also help reduce friction and operating noise.
    Diagnostic Checks & Tests
    Engine Coolant
    Coolant contaminated with black specks can often be traced back to a leaking head gasket or o-rings. Combustion byproducts are forced into the coolant system due to the high pressures in the combustion chamber during the combustion event. These black specks will often float and show themselves as soon as the radiator cap is removed.
    Gearbox Oil
    The composition of the gearbox oil can provide a lot of clues as to what is happening within the engine. For starters, what color is it and what is in it? Oil that appears milky is a good indicator that moisture is finding its way into the gearbox oil. The most common culprit is a faulty oil side water pump seal.
    A keen eye can spot various metallic particles within the oil itself. Aluminum will appear silvery gray. Bronze particles will have a gold shine. Ferrous particles will be dull and are often more discernable by dragging a magnet through the oil. Accumulation of all of these aforementioned particles will be normal in small quantities, but excessive amounts of any of them could be cause for concern. Fortunately, since gearbox and power cylinder lubrication are separate the number of causes for problems is limited and more easily pinpointed.

    Other than changing your gearbox oil regularly, keep an eye out for metallic particles, as those can be a sign of accelerated wear on internal parts.
    Cylinder Leak Down Testing
    While less commonly prescribed on two-stroke engines, performing a cylinder leak down test is by far one of the most definitive diagnostic procedures that can be performed to determine the health of the piston rings, cylinder bore, and cylinder head seal, whether gasket or o-rings. If any of the previously mentioned symptoms are observed, a leak down test is almost always a great next step.
    A leak down test pressurizes the engine’s combustion chamber and compares the amount of pressure going into the combustion chamber to the pressure that is retained. Pressurized air is administered via the spark plug hole and two pressure gauges are used to make the comparison. The piston is positioned at top dead center. Air exiting the combustion chamber can then be traced back to the piston rings or cylinder head seal.
    Compression Testing

    A compression test can be an tell-tale indicator of the health of your top end components. Be sure to compare your reading the manufacturer's recommended compression measurment.
    A compression test aims to quantify how much pressure builds during the compression event. A compression tester which is connected to the spark plug hole consists of a pressure gauge and a one way check valve. The engine is kicked repeatedly or turned over a number of times using the starter. The resulting pressure that is recorded can then be used to assess the health of the cylinder bore. Low pressure readings can then be attributed to problematic piston rings or leaking cylinder head seals.
    Crankcase Leak Down Testing
    A crankcase leak down test is utilized in order to assess the sealing integrity of the crankcase and cylinder. Personally, this is one of my favorite tests to perform because of its ability to isolate a number of potentially problematic seals and gaskets all at once. Components such as crank seals, base gasket, and power valve seals can all be checked to determine if they’re leaking.
    In summary, a crankcase leak down test is performed by sealing the intake manifold, exhaust outlet, and any power valve breathers. Then the crankcase is pressurized under low pressure. Typically, the goal is to retain the pressure in the crankcase over a set length of time. Loss of pressure is indicative of leaks, which can then be traced to their cause.
    Preemptively replacing components before the engine suffers a major failure is both safer and more affordable than dealing with the problem after the engine has stopped working entirely. Most problems that can occur within the two-stroke engine can be mitigated by servicing components such as pistons, rods, rings, bearings, seals, and crankshafts. Many riders dread the thought of having to service these items due to the excessively high costs associated with OEM or premium aftermarket parts. Fortunately, brands such as ProX offer a comprehensive lineup of OEM-quality components at reasonable prices, many of which are produced by OEM suppliers. Depending on what you need to service, components such as piston kits, connecting rods, crankshafts, bearings, gaskets, and seals can all be found in the ProX catalog.
    Replacing components as part of preventative maintenance can save time and money, especially with the availability of affordable, OEM quality parts.
    Find ProX parts for your machine here.
    Discussing specific time intervals in regards to when things should be replaced is futile. The reason is simple: different engines, maintenance practices, and applications will all have different intervals. Installing an hour meter on your engine so that you can log the number of hours the engine has run can be one of the most insightful ways to establish maintenance and replacement intervals specific to your engine, riding, and maintenance habits.

    At their core, backpack-style hydration systems have remained relatively unchanged for some time. Fill the bladder, bite a valve and suck to drink. This design is simple, cost effective and functional, but is this as far as performance-oriented moto hydration systems can go? Is there still room for meaningful improvement? The folks at LiquidAider certainly thought so when they designed and perfected the world’s first push-button wireless hydration system.
    How’s LiquidAider work? Who’s LiquidAider for? What are LiquidAider’s benefits? We caught up with Matt Steele, inventor & CEO of Arapaho Technologies to answer these questions and more.
    TT: Matt, push-button hydration is self-explanatory. What is the rest of the story?
    LiquidAider: The idea behind LiquidAider is that we do not see hydration bladders as a complete solution to hydration. Dangling suck tubes are no good when the going gets tough. And when you are simply exhausted, sucking water sucks! Drinking less at a time but constantly to match exertion is the concept here and by doing that, you will pee less, retain focus and maintain your hydration level.
    TT: So what is LiquidAider?
    LiquidAider: It’s simple: Push button. Drink water. 
    We provide a small wireless button that mounts next to your grip and a small pump that plugs into any hydration pack’s quick connect port. There is a magnetic disconnect that connects the pump tube to the helmet tube. A small adjustable nozzle mounts inside the front of your helmet. As you ride, and I mean in any situation or terrain or speed, you can drink water by hitting the thumb button. No reaching for a tube, and no bite valve. And we add only 8 ounces to your pack, as much weight as a cup of water.

    TT: That’s actually pretty significant. Look at the pictures of any group of trail riders or race photos and even the top pros have a dangling tube not being used. And nobody wants a lot of weight added to their already heavy packs.
    LiquidAider: Exactly true. Staying hydrated is why we all wear hydration bladders. And no matter how good you are, there are times where you need to drink but cannot take your hands off the controls. The harder the exertion, the harder it is to hydrate with a suck tube. LiquidAider pairs with that partial solution and makes it a total solution. Even if you like a bite valve, you can power the bite valve with LiquidAider and not have to suck water.
    TT: So is this only for pros?
    LiquidAider: No, not at all. Our customer base spans all ages and the entire spectrum of casual trail riders, to adventure bikers, road racers, and all forms of 4-wheel off-roaders. I think trials and motocross are the only 2 market segments where LiquidAider is not present.
    TT: What are some of the features?
    LiquidAider: We engineered some very cool features into it. Burst Mode can be set as you ride and it changes the operation to a 2, 3, or 4 second burst of water with a single quick press of the button.

    You can pair the button to any number of pumps so imagine a team race like the Baja 1000. One rider gets off and another gets on the bike. The second rider has his own LiquidAider pump and helmet nozzle and he can use the button to hydrate.

    A magnet disconnect pulls apart to separates the backpack from the helmet. Take off your helmet and it disconnects. Then lay your pack on the ground and water will not run out your pack. With the disconnect separated, pushing the button will not pump water.

    And we will replace any broken part for 50% of the online price. I recall we have had 2 cases where something broke, and it wasn’t the button or pump. In both cases I just sent the parts for free. I was impressed they managed to break something! I know one Canadian rider cartwheeled his bike down a 200 foot whoop section and even without using the supplied button guard, the button was intact and undamaged.
    TT: Battery powered?
    LiquidAider:  Yes. The LiquidAider button is about 10mm wide, and inside of it is a coin cell battery that you can replace. But even though the button never turns off, always is running, that the internal battery will last all riding season if not the year. The pump battery is rechargeable. It will pump somewhere up to 40 liters before needing a charge.

    LiquidAider can be used with virtually any hydration bladder, even children's.
    TT: Care to drop some notable customer names?
    LiquidAider:  (Laughing) Ha! Well, we have shipped LiquidAider all over the world. We have a lot of talent trusting our product to give them a major advantage over guys with suck tubes. 
    Certainly not a complete list, but Jackson Davis (factory Sherco racer), Ron Ribolzi (7x ISDE), David Knight (5x FIM World Enduro Champ) all use it. Cody Webb has been extremely generous to us by using it and testing early versions, and we designed the button to fit his available bar space. 
    At the Mint 400, Damon Bradshaw picked up a kit and then brought a friend over to buy one. Then Damon, as nice a guy as you’ll ever meet, stood at my vendor tent for about 45 minutes demonstrating LiquidAider to desert racers who probably didn’t know who he was!
    Mason Klein who I met at the Parker 250 race this year is 18 years old and finished 3rd in all stages of the 2020 Sonoran Rally except the first one. This means he finished behind Ricky Brabec and Skyler Howes but ahead of a stellar cast of racers and he credits LiquidAider for contributing to his amazing performance. Mason gave us a video of his thoughts about LiquidAider and it’s on our website and YouTube channel.
    We do not pay anyone to use LiquidAider, so if you look over and see our button on the handlebars next to you, it’s because they bought a key advantage to beating you and they know it! 

    Factory Sherco rider Jackson Davis hydrates in the heat of battle with LiquidAider.
    TT:  Is it difficult to install?
    LiquidAider: No, it’s actually easy when you realize all you are doing is installing a nozzle inside your helmet, plugging in our pump, and connecting the tubes with the magnetic disconnect. I highly recommend watching our YouTube videos because it makes everything really easy to understand. Our included written instructions are over the top in detail for anyone wanting that.

    Handlebar control switch  is easy to reach and takes up very little space.
    TT: And what is the future for LiquidAider?
    LiquidAider: We are aware of other applications including military, bicycles, etc. and we are pursuing them. Ricky Johnson helped another entity with a similar concept, probably focused on Trophy Truck racing, but I heard they had issues and are not to market. The technology involved for such a simple concept is very advanced and challenging to implement. We’d welcome conversations with anyone about partnerships or applications. As a side note, I gave Ricky a kit
    when I met him at King of the Hammers in February and he seemed genuinely blown away at the product quality and packaging and I think it caught him by surprise that this existed in a final production form. I hope he uses it and gets back to us.
    TT: Closing thoughts Matt?
    Think about this. We have done everything to our bikes and spent a ton of money to upgrade and give us an advantage over the next guy or just be able to ride better. Suspension tunes, anti-vibration additions, pivot pegs, steering dampers, billet everything. Then a guy goes riding/racing and hopes his body can do what he asks and comes back to the pits with half a bladder of water and is wiped out for a day of recovery. The bike is perfect. The body is shouting “Hey! What about me?!”. LiquidAider is the one thing that you can do for your body, right now, and have an immediate advantage over anyone with a suck tube. All things being equal, the rider with LiquidAider will win every time. And it’s not expensive. Why would you not want that major advantage?
    TT: Thanks for taking the time Matt!
    LiquidAider is available at https://liquidaider.com. Use coupon code : TT20 for $20.00 off & free shipping (US orders).
    You can follow LiquidAider on Instagram and like them on Facebook @LiquidAider.
    YouTube videos make the installation and operation very simple to understand.

    Paul Olesen
    How many of you become disheartened when spokes break, bend, or a rim becomes permanently damaged necessitating a rebuild of the wheel? I know a lot of people think rim building is a black art and are willing to shell out serious dough to avoid the job altogether. This week I want to debunk the black art of wheel building and provide you with an overview of the process, allowing you to take on your next wheel build yourself. Next week, I’ll cover the second half of the project by showing you how to true the wheel.
    As you can see I have a great example of a wheel assembly that is way past its prime. The spokes are bent, loose, and the nipples are mostly all stuck. On top of that, the rim is cracked in a couple spots necessitating further repairs.

    Before getting started disassembling the wheel, measure the distance from the rim to the ground. When the wheel is built the rim will need to be blocked up at approximately this height. Blocking the rim up will make the wheel much easier to assemble.

    The spokes will be offset from one another. Often times this offset necessitates the use of different length spokes. The spoke kit I received came with two different length spokes and there was no indication of which went where. If there are no instructions provided with your spoke kit and your wheel features spokes of different lengths you will need to determine the correct layout of the spokes. This can easily be done by removing two of the old spokes, measuring them, noting their lengths, and positions.

    Once you have determined the spoke length you can go to town cutting the rest of the spokes out of the rim using a cutting wheel or other suitable tool.

    Remove all the old spokes, then closely inspect the rim for damage. On my rim I had two nice size cracks I had to deal with.

    Once the rim has been replaced or repaired, preparations for lacing can begin. Since the wheel will be exposed to dirt, mud, water, and whatever else nature throws at it, I like to coat all my spokes with anti-seize before assembly. The anti-seize will provide a little extra protection against corrosion and help keep the spokes turning freely for a long time.

    Separate the spokes according to their lengths so that there is no confusion during assembly.

    Next, center the hub and block up the rim. Refer back to the measurement you took to establish the correct block height. As long as the rim is not offset to one side or the other it will not make a difference whether you start with the sprocket or brake side.

    The outside spokes will be laced first. If you try the inside route you will quickly find that maneuvering the outside spokes into position won’t be possible. Simply install a spoke into its corresponding hole in the hub then align the spoke with its corresponding hole in the rim. The rim may require some rotating to align the spoke with the correct hole in the rim, however it will be glaringly obvious where the spoke must go since the holes in the rim are all angled.

    As the spokes are installed, thread on nipples to retain the spokes. Only engage a few threads as you install the nipples. Keeping the rim loose will allow all the spokes to be installed easier as you go.
    Once all the outside spokes have been laced in one side, lace all the inside spokes on that side. Don’t be afraid to pull the rim a little bit from side to side to help generate enough clearance so that the end of the spoke can easily pass through the hole in the rim. The rim may also have to be moved up and down a little bit to help center the spoke.

    Next, flip the wheel over and begin lacing all the outside spokes on the remaining side. Pulling the rim from side to side and up and down will be necessary to get all the spokes aligned with their respective holes. By the time you are finished lacing you should have a nice fresh wheel assembly.

    A good way to check to make sure the spokes have been installed correctly is to compare the thread engagement on each spoke. With all the nipples tightened only a few turns the remaining threads showing on the spokes should be about the same. If the remaining thread length is vastly different between the inner and outer spokes there is a good chance the spokes have been installed incorrectly. If this is the case, the longer spokes will need to go where the shorter ones currently reside to even things out. If this isn’t done, there is a good chance some of the spokes will run out of threads when the spokes are tightened.

    After the wheel has been laced, the nipples on all the spokes will need to be tightened with a spoke wrench. Tightening of the nipples should be done evenly and gradually. An even pattern can be used to tighten the spokes so that the rim does not become offset radially in one direction. Most wheels either feature 32 or 36 spokes. Every 4th spoke can be tensioned to create an even 8 or 9 step tightening pattern. Once this pattern is completed, the next spoke in the sequence can be tightened and the whole process repeated until you have worked through all the spokes. In the picture below all the red arrowed spokes are tightened first, followed by the greens, then the yellows, and finally the blues.

    As the nipples are tightened, checking for evenness among the remaining threads is a nice way to gauge symmetry. You may find that there are small differences between the inner and outer spokes in relation to the remaining threads left on them. Instead of comparing the inner and outer spoke threads to one another, only compare similar length spokes as you work. The more care you take to ensure the spokes are tensioned evenly now, the less work it will be to true the rim later on.

    Check to make sure that the heads of the spokes fully seat in their holes in the hub. Some heads may get hung up and will require a tap with a punch and hammer to seat them. Relying on the nipple to pull the head into position doesn’t always work well.

    Another sign that the job has been done properly is that the spokes will not pass through the ends of the nipples.

    At this point you should have a rim that feels tight, is tensioned evenly, and is ready for truing.
    Do you have any helpful tips you want to add? Please leave a comment below and share your experiences!
    Paul Olesen
    DIY Moto Fix - Empowering And Educating Riders From Garage To Trail

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