Ok so here's what I got going on. I am far from mechanically inept however small engines are not my deal. Having said that I am also a single father with one hell of a mortgage and I am sick of spending my money fixing this lawnmower every time I have an issue with it. SOOOO here we go: I was in the backyard mowing (obviously) and I inadvertently hit a large chunk of wood that I suspect my children were messing with. Needless to say I hit it. It still starts and all no vibration, I even checked the bottom end of the crankshaft and it's not bent. Since it still starts I don't think it's the flywheel key. The engine sounds like the valves are hitting. On top of that when I release the bar it stays running! after a little about 30-45 seconds it finally dies. Also it boggs down real easily. Any suggestions?