DRR 50cc WONT GO !!!

[oldschoolyamaha]

I have a 2006 DRR 50cc with the new 2011 Aluminum cylinder and head. It has a Stock 90 pipe, 782 Belt, Red Main spring, 2000 Stall springs, 3.75 Rollers, Keihin PE20 Carb with a 105/50 jets. When you give it gas, it moves slowly and doesnt seem to want to go. Seems to have no take off power... The mid to top end range seems fine. Any suggestions?

[Steven623]

Try lighter roller weights, then it will work.

[kfx450]

you need a 1000 main spring. Depending on what brand of red spring you have may be a 2000. also our stock clutch with a stock cylinder or stage six will shift into high gear before take off if we run any higher than a 1000 shoe spring. def sound like a clutching issue and maybe a little big on the pilot

[fomospede]

clutching maybe
but off the bottom with nothing check vacuum and crank pressure maybe another prob starting to appear

we did use a ztr 1k spring at first then had better luck with the hebo

[doonanracing]

Sounds like the clutches to me. Try a 1k Torque spring and maybe a 1 or 1.5k shoe spring. Then adjust the weights accordingly til you get the performance you want. Also may want to look at the main jet's color to make sure it is jetted properly. Here is a rule regarding clutch set up: By using harder clutch springs the clutch will engage at higher speeds when the optimum RPMs is achieved resulting in a much better pull from a standing start. The goal is to achieve this range.



Here is some other information that might help:
The rear torque-driver spring also has a very specialized function which is to maintain enough tension on the belt to keep it from slipping. This also is a bit of balancing act because too much belt tension translates to inefficiency. It’s kind of like over-tightening the chain on your bicycle- power is wasted by over-stretching the belt. On the other hand, too little tension and the added power of your recent engine modification will vanish as heat generated by belt slipping and won't find its way to the rear tires. The trick is to find the just the right tension without overdoing it. A secondary influence of the torque driver spring is that it has a slight impact on shift speed since the belt tension needs to be reacted against by the front sheaves. The higher belt tension tends to push the belt deeper into the front sheaves making the ratio higher, and revving the motor higher. Therefore, for a given desired rpm you would need to compensate with a higher roller weight to bring the rpms back down. After a torque driver spring change, it’s good practice to re-optimize the roller weights.

[hotquads1]

as steven623 said , lighter rollers , maybe try 2.75 if you are running the 90cc pipe .