i am having trouble getting my carb set up on my 400, i have a k&n, removed air box lid, and a sparks racing exhaust (the cannister has been shortened as well). When i put the k&n on i put a 155 jet and had the needle set on the 3rd from the top groove. (Dyno jet kit) and it ran super, now that i have put the pipe on i have jetted it up and down (back to a 155 now) and just moved my needle up another groove, then after i got it running the plug fowled so im at a stand still until i have more free time to tinker with it, any advice would be appreciated.

 

i think you'll need atleast a 155 djmain jet with that air box lid removed, probably a 160 or 165 will be better.

go buy 2 new spark plugs, put in the 165dj main, needle on 3rd groove and fuel screw 2 turns out.

start it up and go for a ride, watch the throttle position and if it bogs or spudders in any part, remember how much throttle you had on then figure out which jet comes into play then.


if it seems like its sputtering, put the airbox lid on...if it gets better then you are too lean, if it stalls then your way to rich...


i'm not sure if you need to change the pilot jet, some exhausts you need to change it, some you dont..