Originally Posted by mtpocketsracing

I think you have a few things going on.

1. the clutch isn't engaging if the engine is reving and it's not going. this is also the reason for the stalls more than likely. if it has the standard kind of clutch the spring is probably broken. then the shoes get jammed in the housing causing it to stall out sometimes.

2. since it's reving that high on it's own, you have an air leak in the carb. check the base oring and make sure the carb is down all the way and the retainer nut is nice and tight.

any time a nitro engine starts stalling for no reason the first thing you should suspect is the clutch. I've even had a pin in the flywheel back out and touch the bell causing stalls.