My wife has an 08 KLX 140 and when we start it cold it idles great and seems to run normally. After 15-20min of riding and the engine is nice and hot, the idle is way to fast. If we stop for 20-30min and start it up again, the idle is back to normal. I have checked all the cables, choke, throttle, etc. Nothing wrong. The only way I can get it to idle fast is to ride it until the engine is hot. Any ideas on what may be going on here?