Was riding the blaster around the yard, Was in 2nd gear, and all of a sudden the blaster was reving wicked high and my finger wasn't on the throttle, i got scared, i shut the engine button off, took the key out, and was running away, and it still was running, wicked high rev i thought it was going to blow. and after about a minute, it was reved all the way down, then shut off. i tried to start it back up, and it won't. it lost some compression in the kick start, and it's not a blown piston because the kickstart would sieze up. and i just don't know what's wrong with it. We popp start it, and it only stays running for about 20 seconds. and thats it. Any help? Thanks!