RE: Piston rings Os 50sx
$ 20 is high for a piston ring, granted. I think you must use the O.S. part. The question you should ask yourself is: am I sure that's all I need to make this engine 100% again? Will the old cylinder break- in with the new ring? Is the rod, piston, front housing good? Add it all up, plus shipping....I like O.S engines, but doesn’t take much to make it a throw away. Bearing changes are easy and cheap thou.
I have two boxes under my work bench with old engines and old servos/receivers that are not worth sending in for repairs, out of warranty/void of warranty (damaged). Sometimes I cannibalize for parts. O.S...... Hummm, that's short for what I say when they die.
Please don't take sick RC stuff to swap meets to pass them off as good & working, tell it like it is. We RC'ers are better than that!