I have an 05 Raptor that I put an HMF full exhaust system on. I've run it without jetting it and it ran just fine. When I put the recommended jets in it (150 Left, 155 Right) I noticed a misfire in the high RPM's. We tried adjusting the air mixture and did all the recommended adjustments but got no change. If anything, it got worse. If I shift gears sooner it doesn’t happen. Anyone have any suggestions?

 

Your lean, fatten the main up. To see if I'm right, pull the choke on slightly and take it for a pass. If it cleans up you need to fatten it up.

 

Thanks for replying to my post Doctorturbo. I've tried you idea already but it still has the same problem. We think we may have gained so much horse power that I'm hit the revel emiter a lot sooner. As I said before, if I shift gears sooner it dosen't happen, that is until I peg out in fifth gear.

 

is all you have on it is a hmf pipe?