jetting ? backfiring and popping

[jetboy_05]

i have a 04 yfz450 proflow intake with k&n, w/o box lid, and i

have a revbox, also i live in utah about 5000ft above sea level,

my jeting is 160 main 48 pilot fourth on clip and about 1 1/4 turns

out on fuel screw. my problem is when its in neutrel. i rev it

up, about three times and it pops when the motor goes back to

idle , and a flame shoots out of the stock pipe. the flame would

tell me its to rich, or can it do that if its to lean does anyone have

any suggestions

[gotwarrior]

Why don't you put a new spark plug in it, and check and see if its rich or lean.. (I would say it rich)

[jetboy_05]

if its running rich what do you suggest i richin up?

[04450rrider]

If it is running rich u would obviously lean it down. Try a jet size or two and check ur plug.