I didn't plan on cleaning all of the tin spotless since I just wanted to stop the engine from smoking. Other than the smoke, the engine ran great and there was no valve noise. After pulling the head, I could see stake marks around the valve seats, so someone replace them at some point. Also, there was actually a puddle of oil on top of the piston and I could see that the ring gap in the top compression ring was excessive.I slid a new std. piston ring down in the bore and came up with .014, so a set of new rings would make a world of difference.The cylinder was in real good shape, but the piston looked pretty worn.The used piston from the 23d was .003 bigger in diameter at the skirt, so that would help. The NOS rod was tighter by .0015, so that would tighten things up on the bottom end.
I lightly honed the cylinder, installed the piston assembly, and put the engine back together. I installed a new front crankshaft seal, oil pan gasket, carb manifold gaskets,a front cover gasket,and a new head gasket. I fired it up just before dark and it runs like a top! I'll retorque the head tomorrow and use the tractor to go get firewood.
Edited by classic, November 21, 2014 - 06:21 PM.