I have a kohler ch20 that just died on me. Ran a compression test and both sides only measured 25. One spark plug was dry and the other was covered in oil. The engine has 2478 hours so its probably time for another lol. I'm going to tear it down to see what all needs place. Going to go ahead and replace all gaskets, piston rings (maybe even pistons and valves). Anyone wanna take a gander at what this could be and is there anything else I might as well replace while I have it tore down? Thanks PS. Are these engines sleeved?