Wow- very helpful thread as I happen to be cleaning up a collection of engines. Right now working on 30-40 yrs old engines that are really stuck tight with castor. 15 min in a 220deg toaster oven will usually let the crank rotate a little, then I take the head and back plate off and put the whole mess in the crockpot. If the bearings feel smooth after the soak, can I then just rinse out the crankcase, oil it, re-install the head, backplate, and carb, and then test run it? (IE: an antifreeze soake doesn't always mean a bearing and sleeve removal, right?)

Also- if I can see the ring-split located within the exhaust port area, do I need to disassemble the engine and relocate the split?