popping and cracking

[dobber21]

i have 03 400ex no motor work its got a yoshimura pro comp RS-3 full system exhuast and a 170 pilot jet.

i was racing last sunday and it was like 90 degrees and pretty humid and my quad was cracking and popping both races, im wondering if anyone else has had this problem im wondering if its to rich or lean or wat and it was puffing some blue smoke

if anyone has any ideas i would appreciate the help

[dobber21]

oh yeah the clip is on the second slot air box lid off and that was the main jet sry

[drew416ex]

Im assuming you mean you have a 170 main jet. In that case you are way to rich. Go down to a 150-155 main, needle in the middle, and a 40-42 pilot jet. That blue smoke is just a little oil burning.