My Kazuma 150 has a weird carb issue. Its running great, pulls strong, no break up or anything. when I stop and let it idle, it idles so high, high enough that the quad is trying to move. Sometimes it will idle really high for about a minute then finally go back to regular idle rpm. sometimes it wont slow down and I have to turn it off. The carb is stock and it has a k&n style cone filter on it instead of the airbox. I am not a carb expert at all. can anyone point me in the right direction?

 

Most obvious thing is the carb slide or butterfly sticking slightly open, or the cable sticking. If it is a CD carb, the dashpot piston may be sticking. Lots of other possibilities, but check them first.