here is a Kawasaki 23 HP engine off of a John Deere 757 737 The pics will show you what happens when the cooling fins on your head get clogged. This one got hot seized the valve to to the head, snatched the insert out of the head, the valve fell on top of the piston and seized the engine. The cylinder might hone out clean if that is only aluminum in the scaring of the cylinder. If not you can have it bored out for $80 bucks and put over sized pistons and rings in it. But the problem that caused it to happen in the first place was an oil leak. So you have to replace the bushing in the block and in the crank case cover along with both seals.. I can do this for you if you need me to.