so i had my quad rejeted after i bored out the cylinder 1 size bigger and put a wiseco piston in it i have a fmf megamax II exhaust and the thing runs terrable ill start it up and it'll run fine but after it warms up and i ride it it backfires (pop's) if i let of the gas.... and the idle seems to run hi but if i turn the idle down it wants to kill i'm pretty sure they screwed up the jetting at the moron dealership but what do u think and how do u think i can fix it??oh and it seems to take a lil bit to rev down.

No one can help with this??

Come on no one has any input on this??