I checked the jetting posts and none of them worked for me so here is what I have. Stock jetting, air temp is 25-50 degrees, altitude of 5,200', FMF Q4, Delkevic header, 06 CDI. The bike backfires when letting off from 3/4, 1/2, and 1/4 throttle. Do I need to raise the needle or change the pilot jet or both? It seems to smooth out a little in the 1/2 to idle range when I have the air screw turned out 2 1/2 to 3 turns but that's a little much for my liking. Thank you.