I'm used to loud, open
Pipes. It's the rpm. My 1st gear winds out at 5mph, 2nd around 10. I have to be in 4th gear to hit 25mph! I have some needle shims, Ill try that buy I don't see what that would have to do w/ reaching too high an rpm @ too low a speed????
It controls the fuel mixture from 15% to 60% open throttle. It sets in the center of the carb, right over the main jet.
Jet Needle. This is the needle that rides in the throttle slide and goes into the needle jet. This needle controls the fuel mixture from 20% to 80% open throttle. It can come in many different sized tapers. Sometimes, one needle can have several tapers on it. The top end of the needle has grooves cut in it, usually five, and you can move the little clip on the end up or down to lean (down) or richen (up) the mixture.
Thise how I meant about your bikes rpm problems.