Lost compression going home the other day (oh  oh!).  Must have overheated a bit.  Let it cool and made it home.  Then yesterday I tore it down to check the piston/rings.  Not bad looking, but got a new set on order.  Bore looked Bee yoo tee full.  Not sure why it did that.  Valves look good.  I suspected rings when I saw excessive blowby from the breather once.

Will have it back and running by the end of the week, with fresh black paint on the cylinder.