I have O.S. Max engines that are over 36 year's old. I've never had to change a rod. I have changed the bearings every couple of years. Of course I never leave fuel in my engines and always use Marvel Mystery Oil after a days flying.

Also, the lower rod end should a very small amount of play. I think it was Clarence Lee that stated that the little amount of play is what lubricates the bushing. And if anyone knows about engines, it's Clarence Lee. You can catch his articles in Model Airplane News.

Frank