run's like crap with no lid???

[mjtwvc]

Just wondering why my 450 run's like crap with the lid off and my brothers yfz seem's to run better with it off and with a k&n.
is my stock jetting farther off then his?
his won't idle very good and mine idle's almost perfect . :confused:

[lukester720]

You're running way lean with the lid off and stock jetting. Rejet it or put the lid back on before you tear it up.

[jmoney45]

and tell him to rejet his yfz if he hasn't, but i have to believe he has since he has no lid and a k&n. if not he is WAY lean also.

[Toadz400]

Yea you definately need to rejet without a lid on. On my 400EX it runs like crap if I put my lid back on because it's jetted richer for the increased amount of air. You will most likely end up frying something if you don't rejet, tell your buddy with the YFZ too...or if he's too lazy/dumb to do that, tell him I'll happily buy it from him.