I was here a few months ago keep asking about oil ratio. I think I learn my lesson. I have been buying old trimmer engines on ebay to take apart for learning purpose. I have to say, all the old engines, 3 freezed with deep scoring on cylinder wall, obviously the engines ended their life when owner forget to put oil. 3 of the other have heavy deposits. The Echo SRM260 engine have the top ring stuck tight in the groove. ALL the engines I looked at, the rings were no where close to wearing thin and except for one, bearings are pretty tight, no loose space. This tell me very clear lubrication has not been an issue, it's the other stuff ( like no oil!!!! or may be too much oil!!!! ) that can cause more problem. I am sure, if it is not because of the mensioned problems, those engines still have a long way to go judging by the wear only. Six engines might not be a good statistic, but six out of six do tell something. I have to start agreeing that the little less wear that MIGHT be gain by more oil might far more offset by the potential of other problems that can cause by too much deposit. Well.....50:1 it is. Just hope I have not put too much deposit in my Shindaiwa C4 blower after using about 5 tankful of 32:1!!! Well, if you are willing to take it apart to clean it, then it will be a different story. I don't think 2 cycle engines are too hard to take the cylinder out and clean. Is it true then, those 4 cycle engines with no oil in the gas should stay cleaner in the long run given everything else are the same( assume well tune carb )?