rotor oil seal o rings might be getting tired, thier job is to keep oil from leaking into the chambers after you shut it off, https://www.nopistons.com/forums/pub..._DIR#>/sad.png it should run forever, and if you pull the motor apart the smokers usually look brand new

So not as big of a concern as I had anticipated then? Just watch the oil.

Oddly enough my old engine did that sort of thing too, but I later came to the realization thatI put to much oil in when I had changed it last. I was getting HUGE clouds of smoke on startup as if the seals had gone but then about a week later it went away and never came back.

it will just keep getting worse until it smokes all the time, and then you gotta pull motor and rebuild