got an 06 yz250f. it used to run perfect, start on 1st kick, be very responsive, and it would also idle perfectly cold or warm. i laid it over cracked my stock header, so i bought another stock header and muffler off of an 09 yz250f and have recently put a boyseen quickshot on the carb. ever since i cracked the stock header pipe and ruined my bike really hasnt ran the same so im taking a guess its jetting and/or air screw so can somebody please tell me what kind of jets and what position my air screw should be in for the 09 header and muffler? thanks for your time and any ideas or help would be great.