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About tc66nova

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    TT Bronze Member

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  • Interests
    Drag racing,dirt biking,bow hunting
  1. tc66nova

    Quick Auto Decompresser Question

    B.S. I have hundreds of hours on mine with NO detectable wear and several others on this board have more hours, miles, and races than you can count with out any problems.
  2. tc66nova

    rekluse clutch 450 on a 426

    I don't have any idea about interchangeability between the 450 or 426 but I just bought a used rekluse for an 02 426. The instructions and parts list that came with it are signifcantly different from the instructions and parts list that I downloaded from the Rekluse web site. I had to order several more drive plates ($5each) and another gasket ($20). YZ426 rider is right that their customer service is very helpful, give them a call and ask.
  3. tc66nova

    Head pipe

    The expanding cross section is necessary because exhaust gases are rapidly expanding as they exit the cylinder and continue to do so as they travel down the header pipe, therefore the introduction of stepped headers in various types of racing. The combination of pipe size and velocity is critical to an efficient exhaust system as cooling gases in a restricted pipe will cause inefficient cylinder scavenging and therefore reversion of exhaust gases back into the cylinder during the valve overlap period causing a dilution of the incoming charge and a measurable loss in power. As for no one performing scientificly based dyno pulls to prove or disprove the many theories about exhaust gas control, look into either F1 engine designs or the world of Prostock drag racing and you will be surprised. And lastly as for the head pipe heating the radiator where it is in close proximity, I to feel that there is enough air flow at speed that the heat is probably negligble. But while sitting still it definetly puts heat into the radiator. Just picture the induction harding process where steel is heated to very high temperatures in just seconds by being exposed to a heated coil with a space usually larger than 1/4 inch seperating the coil and the item being heated. Now start your bike at night and notice the red glow from the pipe in the area near the radiator or try to hold your hand a 1/4 inch away from the pipe and you will see or feel the heat that would be transfered to the lower part of the right radiator.
  4. tc66nova

    Head pipe

    In theory yes, hotter exhaust gases make more power. The hotter gases maintain velocity in the pipe and therefore should scavenge the cylinder better. MAX power is usually achieved at or near max cylinder temp before detonation occurs. That point is different with every motor and with a dirt bike your riding style will have a ton more to do with your lap time than the negligble power increase from cooling the motor more or keeping the exhaust moving at max velocity. That being said, there is more to be gained from keeping the intake charge cooler than fron keeping the exhaust gases hotter/faster.
  5. tc66nova

    my 2001 426 wont start

    I will also say change the plug. And yes you need the auto decompression cam. I would have have sold my 02 426 by 03 if I had not made the switch.
  6. Stumped, where do you live? If you are anywhere near Ohio I would be willing to help you out.
  7. Do you know a COMPETENT machinist? I fix that sort of thing all the time. But if you are not qualified and or don't have the right equipment DO NOT touch it. I have fixed alot of broken bolts that took a couple of hours that the owner had tried himself. With the right tools it usually takes just a few minutes. The right way to do it is a center drill to locate and then try a left hand drill. Usually the drill will catch as it goes thru and run the bolt right out.
  8. Any bike salvage yards in your area? Other wise try e-bay by typing in the specific model of bike you have and doing a search.
  9. tc66nova

    Are All Brake Fluids Created Equal?

    I don't know if the valvoline is pure synthetic or not, but I don't think it is. If it has not caused a problem yet it probably won't. In our cars it usually took a week or so before the brakes would start to drag. Then during hot laps it would lock a caliper. Going back to a standard dot four and replacing all the seals in the system fixed it. It always seemed to affect the calipers more than the master cylinder for some reason.
  10. tc66nova

    Are All Brake Fluids Created Equal?

    IGNORE the boiling point that is prominetly printed on the container. Look at the fine print for the wet boiling point. You will find that it is much lower and nearly equal among most brake fluids except for synthetics, which as already stated should not be run in our bikes. As SOON as you open the container you are dealing with the wet boiling number because brake fluids (except for synthetic) are hydrophillic and absorb water. The water is what boils, creating gas bubbles in the line, causing poor brake feel. Use a name brand and change it yearly or more often and save some $. Brake fluid has the amazing ability to absorb moisture even in a closed system. The moisture is also what destroys the components in your braking system. By the way synthetic in a non synthetic system causes seal swelling which has the nasty habit of locking brakes on once they are applied. I have personaly experimented with all types and brands of brake fluids in race cars for several years where we really abuse braking components. So for what it is worth I thought that I would share what I have learned from experience.
  11. They should be a matched set. I am not saying that you could not replace one side though. But I don't know if a dealer can or will sell just one side. Most split case engines are finished machined as an assembly for the crank bearing bores to make sure that they line up perfectly.
  12. tc66nova

    Anyone interested in a Revloc??

    I second that, How much?
  13. tc66nova

    Finger operated gear shifting?

    The drag bikes usually use an air cylinder conected to the original shift lever. The problem is that they are designed for upshift only. You have to manually down shift the transmission. I think that the system would be to bulky and fragile for a dirt bike. But it would be cool.
  14. I have and love the Dr D. I do lube it every few months but that is it.
  15. tc66nova

    Galled Cam Journals

    I agrre and disagree at the same time. You can definitly distort the cam cap and even the head itself by over tightening the bolts. That is why torque plates are commonly used when boring cylinders. But to distort the cam bores enough to cause galling is doubtful. I still believe that most galling problems start when guys rev the engine before it is THOUROUGHLY warmed up. Oil flow is sluggish until it is warm and the clearances are tight until the the engine is up to temp. Remember that aluminum has an expansion rate nearly ten times that of steel. So the running clearance at temp is alot more than when the engine is cold and there is little oil flow. Bore distortion and oil flow issues have been a major concern in the racing engines that I have been building for the last thirty years. In my drag racing engines we always heat the oil and water before we fire the engine.