having fun now probablly means he's having fun fixing it i guess. yeah just pop the head off and look for a sticking valve, did you check for gas and spark from the engine, does it generate spark while the plugs hooked up but hanging out, and does it get gas. if it has no spark you could have a corroded connection, sheared key, or bad coil. # of things can be it. but if it gets little to no spark, try and check the flywheel key. that may be sheared if you hit something.