I went back and checked the engine. When I rotate the crank by hand, I can hear that there is some play in SOMETHING. I know, not very helpful or descriptive.
I would call it excessive play, but I'm not sure that it is, excessive. There is NO movement of the crankshaft when I try to work it laterally (vertically or horizontally) but when I rotate it by hand, about 1/4-inch of rotation, I can hear a clunk. What it seems like to me, is possibly the camshaft gear has some play in the gear that mates with the crankshaft. Or, possibly the governor gear?
I don't know how much play there shold be, but it sounds like mine might be on the outer edge of allowable specs. All of this is from my un-educated experience so, I could be dead wrong. Maybe it's normal.
I'm considering whether to buy a gasket set and prepare for a rebuild. I've determined that if I'm going to crack the seal on the engine, i might as well do it completely. I've done various V-8s over the years but this would be my first single cylinder engine in quite a while. It would be good to get back inside to refresh my memory, but if I don't have to...
But, I want to re-paint the tractor and if I'm going to do it, now would be better than after the paint dries. I've been known to over-think things and I'm trying to figure out whether that is the case here or not.
Anyone got any insights, encouragement or, just eager to see a fellow Kohler owner jump off the cliff?