04 Yz450 And Powerbomb Header

[GENE426]

I Have A 2004 Yz450 And Put A Powerbomb Fmf Header And A M4 Muffler It Look Just Like A Fmf Muffler And It Seem Like It Backfires (pops As I Decelerate) More Than Normal, Whats The Jetting Suppost To Be? Im At 700 Feet In San Antonio Tx And Know Squat About Jetting

[GENE426]

Sorry 400 Feet

I Ride In Floresville Tx

[rucka356]

Mine did the same thing when i put a pc muffler on. Turn the fuel screw out a quarter turn. If it pops more, then turn it back in a half turn so that ur richening it by a quarter turn. You can probably fix this problem my adjusting that fuel adjustment screw!!