I have a 250x and it runs decent but when i pin it or pull wheelies it just goes weird like the choke is on or some thing . It has a pipe and has been jetted to work with the pipe i THINK ? it has a 125 main jet and i white bros header wit suretrapp exhaust . Any help would be appritiated it is a real pain in the a$$ not being able to wheelie . Has anyone else had this problem ?

 

does it bog down when the throttle is pinned?
does it backfire at all when you let off the throttle?
if its bogging down, maybe try removing the air box lid.