I have an OS 46SX that I bought in the late 80's or early 90's. It was used quite a bit when i first got it and it was even dunked in a seaplane crash (Engine sat submerged for about 15 minutes).

Then, the engine was retired for about 10 years and sat on a shelf in either a damp basement or a garage through extremely cold winters and humid summers.

Last year, I put it in my Northstar and it still screams.

This engine has never seen after run oil of any type, nor has it had any kind of special attention whatsoever.

And it's still ticking!