i have a 450 and a rappy and i am clearly not as fast on the 450 as the rappy. i've raced 6 mx races on the 450 and i havn't got a win yet. the only motor mod on the rappy is a slip on. monday i'm having the cam mod
and the jetting done on the 450 will this really help the lap times.

 

just a little bit, put an aftermarket pipe on it, k&n filter kit, if they have one, and a jet kit, i dont even think they have more then a pipe