Jetting question

[skate2ride]

I'm kinda new to this but here goes. I have a 05 400ex with HMF slip on, k&n and a amr stg1 rev box. What I want to know is what jet or jet kit I should use. Thanks Ben

[rooster_20]

I have a dyno jet kit and love it, it comes with every jet you would need and a bigger needle.

[Wheelie]

Airbox lid on or off?

[skate2ride]

I ahve the airbox on but I drilled about 15 1/2inch holes in it for better airflow.

[idontknowwhoiam]

i just put a hmf slip on on my 02 not long ago....lid on...alls i did was change my main jet to a 158 and its runnin real good, just go to your shop or dealer and buy a bunch of jets..they are like 2 bux a peice....