Hi all I just bought a used 04 yfz450 it is 4 months old and has a bad miss just off idle it is ok if I pump the throttle a little and it just great above that it just misses off idle i'm guessing there is dirt in the carb but didn't know if it had an accelerator pump that could be bad I don't know PLEASE HELP!!
thanks
Todd
Morrison Illinois

 

most likely you just need to fine tune the jetting. trying experimenting with the pilot, main and fuel screw.