I have a 2003 400 ex with white brothers pipe high performance cdi box and stage 2 cam staock carb with 168 main jet. It will idle fine cold but once it is ridden for a little while it idles between like 1500 and 2000 rpms. is their an adjustment on this carb to fix that?

 

Big **** on the left side of carb (towards the front). It is slotted, but is serrated and big enough that you can trun it by hand if you need to adjust it out on the trail.

 

I dont recall of seeing a big **** on the carb when i put the jet and needle in it, but i would turn it clockwise to bring the idle down correct? would the air fuel mixture screw have any thing to do with it?

 

The mixture screw may be ok where it is, but it sounds like the idle speed setting may be a bit high, or the clamps holding the carb may have loosened up, and now youve got a air leak, which raises the rpms.
Check to make sure the carb clamps are still tight. Then try backing the idle screw out a bit.

 

found the **** guys thanks. it soesnt look like it would be an idle screw due to its location.