YFM350 starts and idles great. After about 5 minutes the RPM comes up a couple hundred and will not drop back to idle. With the engine off the slide appears to function as you can hear it going up and down. What besides a sticky slide would cause this? Thanks for any help, Tom/Idaho

 

A vacumn leak will cause the rpms to come up. Check the rubber parts, like the intake tube, for cracks, that let air in.