same thing happened to mine using same fuel then guess what it locked up tighter then a drum sent it in for warrenty sent back with new piston sleve and con rod second time around same thing sent it back they sent me a new motor
so i bought an os32 and put the tt in my second heli got about 4 or 5 tanks and knock on wood no problems but i put the head shim in that is the only difference GOOD LUCK

shamoo