jettin or miss fire prob "HELP"

[mulisha613]

so i have my 2004 yfz450 witch i bought like month ago now and im having this problem where im on the throutle and its back firing and like junk i tryed rejetting to a168 with a 45 pilot with 2 turns on the air fuel witch alot of ppl are runing, i have a gyt r slip on and gytr air filter, and runing not air box lid, so its it really my jetting or my is it a miss fire, so wat it doesnt happen when it idels nor when its cold

[CamQuadRider]

You may have a maniflod clip too small for your exhaust i had the same problem, you may also try cleaning carb. Not too much you can do if you have rejetted it.