Re: Engine won't go past 30MPH
I do 30mph (gps verified) and it's plenty fast enough for me. My bro goes a bit faster on the top end...I think about 35mph. These are on new engines, we haven't even fully broken them in yet.
My bike is completely stock with a Sporstman Flyer hub 40T and 29" wheels. I did change the plug wire, but that was because the other was a dud right out of the box. Also an NGK plug.
My bro's bike is stock with a 36T hub, banana pipe, rejetted, new CDI, SBP intake filter, and a bike berry tensioner.
Keef B, are you running a rag joint? One of the things we noticed the most is that going from a rag joint to a hub adapter and sprocket, we have less vibration, smoother acceleration.
Rejetting helps as well as getting the correct fuel mixture. The stock exhaust pipe is better for low/mid range, but I find my bike is lacking up top. My bro's banana pipe helps him pull more top end out of his bike. A proper expansion chamber would be even better.