ok, i bought the modquad k&n kit with a outerwears lid box replacement filter. i installed it all last night and tried riding it this morning with the lid off. when i was in the higher rpms, it kind of bogged out. i put the lid back on and had no problem. is this a symptom of needing to re jet? i have a TRX450r. PLEASE HELP!

 

Only happens at high RPM, so that indicates that it is the main jet. Goes away when you put the lid back on (less air), so that means you are running lean with the lid off (bad for your engine!). So I would try a larger main jet, to run with the lid off.

 

what is the main jet on it? what should i go up to?