i have recently done a engine change on my 50cc speedfight but it seem to be giving me problems. its like when i try to pull off theres no power there then it finally takes off but as soon as it gets to like 20/22mph it dies a bit and stays at that speed.

plzz could someone give me advice

Tyronee, February 2011

the advice i would give is that thew problem is probably due to the exhaust you have on it ,is it a performance race expansion chamber ?if so then your rollers are not light enough just to make the point try taking 3 of the 6 rollers out of the variator and see what its like then, leave three in there in a triangular formation so the variator opens and closing evenly.

adam bike doctor(of milton keynes motorcycle centre), February 2011