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Found 2,798 results

  1. Bigmanjoe450

    '01 CR 250 rebuild

    Hey everyone. I was thinking about buying a blown up 2001 CR 250 as a project bike. My buddy that has it says it only needs a piston and ring kit to get it running again. I'm guessing that there is more that needs to be done with it, but I don't know what to look for. What are some of the things that might need to be replaced or fixed in a seized up 250?
  2. Hi guys, I'm having an issue withy my CR125 clutch. Just after warming the bike up for a ride hopped on pulled the clutch and the bike stopped. Kickstart didnt feel right so I drained the oil and pulled the clutch cover. Found that the outter friction plate had broken and slipped out, part of it getting behind itself which of course chewed up the edge of the outer basket. No broken teeth, just some minor wear. Installed a new OEM basket, friction and steel plates, and new springs. Soaked the plates overnight and put it all back together. When I put the pressure plate back on and torqued the bolts I noticed the outter friction plate was sitting flush to the edge of the basket. Put oil in the bike, warmed it up again,pulled the clutch and the same thing happened. I have the correct basket, plates and springs and all are new, when assembled it just seems like he stack of plates and disks are just too tall. Its a 2004, I have 8 friction and 7 steel plates installed. And yes, total forum newb but long time lurker so feel free to have a laugh at my expense as well! Any suggestions are greatly appreciated!
  3. kwbmxr123

    Computer fans for rads on Dirtbike?

    i did This Recently to my YZ426F. i used a 14.4V Drill battery and 2 computer fans. The key is to getting a clean install so you do not make your bike look like trash and you do not get stuck on wires. the biggest question that i had when looking how to make these fans was how long they would last. Mine last 4-5 Hours. In all of the trails I've done i haven't ever run out of Juice for them. When i am going fast i can flip a switch and shut them down, but i have never had too. View attachment: IMG_2156.JPG View attachment: IMG_2157.JPG View attachment: IMG_2158.JPG View attachment: IMG_2159.JPG View attachment: IMG_2160.JPG View attachment: IMG_2161.JPG View attachment: IMG_2162.JPG
  4. PICKERINGTON, OH – November 27, 2013 – (Motor Sports Newswire) – There will be more opportunity to race vintage motocross in 2014, thanks to an expansion of the AMA Vintage Motocross National Championship Series. The seven-round series will roll through Ohio, Illinois, Michigan, Kentucky and Indiana from May to October. “Vintage motocross is evolving at an exciting pace,” said AMA Motocross Operational Coordinator Alex Hunter. “We learned a lot in our first year, and we are putting those lessons to work in 2014.” New facilities for 2014 include Sunset Ridge MX in Walnut, Ill.; Russell Creek MX in Greensburg, Ky.; and Mammoth East in Paoli Peaks, Ind. Racers also will have additional classes to choose from, particularly expanded non-current classes. “We’ll also be putting into place a new advancement system to recognize our faster riders with well-earned A-class designations,” Hunter added. “As with all AMA-sanctioned competition, riders will have the option of joining the AMA as part of our family membership option or participating using the new one-event pass. “One of vintage racing’s most enduring qualities is its accessibility,” Hunter said. “Almost anyone with an old dirtbike can find a place to race in our series and be competitive. It’s some of the most fun you can have on two wheels.” The program is also shifting to a one-day format for 2014. “Promoters asked that we streamline the program,” Hunter said. “In addition, with several riders traveling to compete, many reported that a one-day format would be more manageable. In making this change, we also responded to organizer and racer feedback and split motocross into its own national series this year.” Rules, schedule updates and class requirements can be found here. 2014 AMA Vintage Motocross National Championship Series Round 1: May 18 Action Sports Moto-Park, Athens, Ohio www.actionsportsracing.com Round 2: July 19-20 AMA Vintage Motorcycle Days Mid-Ohio Sports Car Course, Lexington, Ohio www.americanmotorcyclist.com Round 3: Aug. 3 Sunset Ridge Motocross, Walnut, Ill. www.sunsetridgemx.com Round 4: Aug. 24 Lincoln Trail Motosports, Casey, Ill. www.lincolntrailmotosports.com Round 5: Sept. 14 Log Road Motocross, Coldwater, Mich. www.logroadmx.com Round 6: Oct. 4 Russell Creek Motocross, Greensburg, Ky. Round 7: Oct. 18 Mammoth East, Paoli Peaks, Ind. www.podium1motoplex.com
  5. ------------------------------------------------------------- Monster Energy Supercross - ROUND 17 Sam Boyd Stadium Saturday May 7th 8 PM - 10 PM PST ------------------------------------------------------------- Live Timing: http://live.amasupercross.com/ Race Day Live: http://livestream.com/accounts/1543541/events/5335068 Supercross Race day Live starts: 12:50 AM PST *** Fox Sports 2 Network starting at 7pm - 8pm PST ***Fox Sports 1 Network and Fox Sports Go App @ 8 PM PST http://instagram.com/racerxonline https://twitter.com/pulpmx http://instagram.com/pulpmx http://instagram.com/twmxdotcom
  6. I tore down my 450 to install new faction mx valves. Everything went well and I have put everything back together, the only problem is im missing a hose! I have the larger Breather hose, but I'm missing the smaller one. i know the larger one is an oil overflow in case the bike is laid on its side, but I don't remember what the smaller one is or what it is called, please help me!
  7. Reeve Harper

    KTM 85 powervalve disassembly

    Hi, I was just wondering if anyone knows how to take the powervalve governor out of a KTM/Husqvarna 85. I’ve bought a new spring for it and I don’t know how to fit it, I’ve heard the spring is in the same spot as in the bigger KTM’s but after I take the cover off the bolt underneath (pictured) just keeps turning. Does anyone know? Thanks heaps.
  8. Collin Johnson

    1978 Suzuki Rm 125

    THIS ADVERT HAS EXPIRED!

    • FOR SALE
    • USED

    It does not run and needs lots of love, any questions just ask. I would like 800 or best offer. Nebraska/Kansas area.

    $800.00

  9. Michael-Stevens

    How to Clean your Motorcross Gear

    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/
  10. TeaNCrumpets

    Jeff Herlings to race MX2 in 2016

    So number 84 is racing mx2 again, sandbagging or being smart and recovering from his hip? Personally I don't think mx2 is a gimme so I think he's being smart.
  11. Gary Semics

    Motocross Cornering Skills

    If you've been riding motocross very long you understand how important good cornering skills are. But so many riders develop bad techniques which end up being bad habits. Here's some import techniques you should know and practice in order to improve your corner speed and control: 1. When on a straight approaching a corner as soon as you shut the throttle off you should be braking hard with both front and rear brakes. 2. You should continue to control both brakes or in some cases at least one until you are going to pull the trigger (get on the clutch and throttle) to exit the corner. 3. When braking your body should be a little back or at least in the middle. 4. The most critical part of the corner is the transition. This is where you go from braking to accelerating. Prefect braking control and then perfect clutch and throttle control. 5. Always focus and move your head toward where you want to go in the corner. I hope this gives you some things to try and most of all gets the results you're looking for. Let me know if you have any questions. GS
  12. enduro 4 life

    Help Choosing a Piston

    So rebuild time is upon me on my 2013 kx 250f. This is my first rebuild and was wondering what pistons you would recommend? I race top C class motocross. What pistons have been reliable, better performance ect? Thanks, Dan
  13. Alrighty thumper talk folks I have a 2008 Ktm 250sxf. I was going to replace the inner clutch cover gasket when I (not thinking) pulled the inner cover off the engine without taking the impeller circlip off thus pulling out the shaft pictured. Anyways now that I am at this stage I went to put the cover back on lining the half moon key up it was all going smooth but the shaft that runs the impeller and goes through the cam chain area does not go in far enough no matter what. What the heck! So what do I need to do to get my machine back??? Thanks folks! :thumbsup:
  14. Rock 105.3 Team Rider Desiree Bates gets to chat with a legend out at Round 4 of the CALVMX Vintage Motocross series! Check out the interview with Mr. Gary Jones on Rock 105.3 Motocross: http://www.rock1053.com/pages/Rock1053Motocross/SanDiegoMotocross.html
  15. OwenDennis

    First time racer!

    Hey everyone, Has anyone tried to race a CRF 450X in motocross before? What re your thoughts? I'm planning on doing some Hare Scrambles this year, but would also like to try my hand at a few AOTMX races. I could have bought a 450R but the X just made more sense when I'm just out riding the trails with my family which is what I do most of. i was just wondering if you could even race a 450X. Thanks,
  16. Went to a mototrack in norseman(western australia) its in a country gold mining town so nothing flashy,quite sandy track!! i got the 13t sprocket ejk with position007 settings,powercore4 and powerbomb. The exhaust has a great sound and loud which is what i wanted,my friend took his 490 yz yama quad,another guy had a predator 500 and there was a guy on a crf250x who only did one lap!! The different with this kit is great and turned the grandad bike into a lively toy,it was a bit scarey in some places as the sand gave me a front end wobble sometimes,my friend said it was because i wasnt going fast enough but aner guy said because you have shit tyres???
  17. 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)
  18. white horse

    high rpm cut out

    my recently rebuilt bike starts fine but at higher rpm range its not smooth.only testing in neutral carb is clean mix is a little rich could it be stater
  19. Jethrobolas

    2 stroke piston seizures

    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
  20. RScrf450r

    Mx track

    So I went to my first mx track today. A lot different from the trails and sand pits I've been riding my life. Found out I definitely need to do some suspension work and I need to go more and practice. Good time though
  21. A new Motocross track is coming to Southern Utah/Cedar City Area!!! Check us out on instagram at @DNCRaceway https://www.instagram.com/dncraceway/
  22. LAS VEGAS, NV – December 18, 2014 – (Motor Sports Newswire) – RCH Suzuki Factory Racing has re-signed Broc Tickle to ride a second Suzuki RM-Z450 alongside Ken Roczen’s No. 94 for the team’s 2015 Monster Energy Supercross and Lucas Oil Pro Motocross campaign. Tickle, 25, showed great promise aboard the team’s No. 20 machine in 2013 and last season until being sidelined in March following a pratice crash at the Toronto Supercross where he sustained fractures of the T-6 and T-7 vertebra, two broken ribs and a collapsed lung. Since then, the Michigan rider has fully recovered from his injuries, making it an easy decision for team owners Carey Hart and Ricky Carmichael to include Tickle as part of the organization’s 2015 rider lineup, giving RCH a potent one-two punch heading into next month’s season-opener in Anaheim (Calif.). “I’m really excited to be back with the RCH Suzuki Factory Racing Team for 2015,” said Tickle, the 2011 AMA Supercross Lites West Champion. “We’ve had an awesome two years together and for Carey and Ricky to bring me back after my injury really shows what kind of guys those two are. They stuck with me and kept a spot for me. We were heading in the right direction until I got hurt in Toronto. I’m glad all that’s behind us and I feel great. I’ve been riding and getting ready for the Supercross season for the last month and I’m really pumped with the progress we’re making. All of the work the team has done building and testing with Ivan Tedesco over the summer and fall has definitely paid off. The bike is amazing. “I'm also really excited that Thor, Bell, X Brand and Sidi will be my personal sponsors for 2015,” continued Tickle. “Some of the brands I've worked with in the past with great success and some are new to me. I’m looking forward to building strong relationships with all of them and having a breakout year with RCH Suzuki Factory Racing.” After winning the 2011 Supercross Lites West title for Monster Energy Pro Circuit, Tickle made the jump from the 250 to the team’s big bike the following season. A fifth-place finish in the final 2012 Supercross point standings and a ninth-place end result outdoors netted him a new opportunity for 2013 with RCH. The new combination proved to be a consistent mix for Tickle and RCH, with a solid first season paying off in the form of eighth-place finishes in both Supercross and Motocross season-end points. Last season, Tickle kick started the 2014 campaign with back-to-back eighth-place finishes at Anaheim One and Phoenix before a pair of incidents in heat races at A2 and Oakland kept him from competing in each race’s 450 SX Main Event. From there, the Holly, Mich., rider only finshed outside the top eight once over the next six stops, including a career-best fourth-place showing at Daytona International Speedway before the injury in Toronto. “I’m very excited to be bringing Broc back for a third year with the team,” explained Hart. “He was showing major gains each week last year, leading up to the Toronto Supercross. We’re all looking forward to picking up where we left off, and having a very successful year of Supercross and Motocross.” RCH Suzuki Factory Racing has seen steady progress since Hart and Carmichael formed a joint venture in 2013 and achieved the pairing’s first podium finish in April of this year at Metlife Stadium in East Rutherford, N.J. Always trendsetters in the paddock, RCH continues to show the way with unique marketing initiatives and partnership activations, consistently influencing the feel and dynamic of the pit area. Tickle’s No. 20 RM-Z450 will showcase sponsorship from Soaring Eagle Casino and Resort, Jimmy Johns, Suzuki, Dodge, Sycuan Casino, Bel Ray, and Rockford Fosgate. “We’re glad to have Broc back with RCH for 2015,” said Carmichael. “We were really happy with the progress he was making last year. You could see his confidence building as he got better every week. We all know he got hurt in Toronto but, up until then, he put together some solid races and had the finishes to show for it. We’re looking forward to having him around this year so he can finsh what he started last season. I know that’s at the forefront of Broc’s mind, as well.” The 2015 Monster Energy Supercross season kicks off Saturday, Jan. 3, 2015 at Angel Stadium in Anaheim, Calif. The first of 17 races on the 2015 Supercross schedule will be televised live on Fox Sports 1 beginning at 10 p.m. Eastern Time.
  23. Bryan Bosch

    FMF United by Power | Episode 3

    October 6, 2015 – (Motor Sports Newswire) – The final episode of the FMF United by Power series follows Team USA on race day at the 2015 Motocross of Nations. Team USA fought hard and we are proud of the heart and 100% effort they gave. In case you missed episodes 1 and 2, you can find them HERE.
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