How do i jet my 400ex

[baker400ex]

I have an 06 400ex with a HMF slip on air filter and some screwed up jets......the problem i have is.....when i let off the gas the quad boggs out on me not horribly but its a concirn and compared to my friends 400ex's it seems to have less low end......the jets i have are not stock but any ideas/ jet sizes I should you to solve this problem

[Choppers]

have you checked your spark plug to see what color it is. If not you should check that and tell us what color it is. Could help tell you if it is running lean or rich. Pick would be great also of the spark plug.

[Doibugu2]

Get a 42 pilot jet and somewhere between a 150-155 main jet. That is assuming you have your air box lid on. Will depend on your elevation though.