backfire sometimes

[gsxtc]

well i just put the nnew hmf on my quad, it twas jetted for a fmf exhaust. the quad runs real good but everyone in na while, not much at all it twiill throw a lil flame annnd backfire, thte hmf came wiith one jet and i believe it says 180 on it?

[44oEX]

don't put a 180 you only need something around 155-160. if it backfires all you have to do it unscrew the mixture screw, only do about 1/8 of a turn at the time and see what it does. it you take it out to 3 turns you need a bigger pilot jet

[maynard22]

I have a thread elsewhere on here about this, but the guy at the local shop put a 180 in my bike, is that way to big? I have a t4 slipon, fmf headpipe, and holes in the airbox. I live in Oklahoma, and I don't know the sea level

[Joe400ex]

my exsaust back fires to and i somtimes shoot flames is this bad

[44oEX]

if it shoot out flames you are way to lean on the pilot. and yes a 180 is to big I would think, check the plug to be sure, but a 155-160 would probably be better

[gsxtc]

it doesnt backfire all the time just sometimes when i let off

[44oEX]

well then just unscrew the mixcture scew a little, like 1/8 of a turn, and see if it stops.