Re: Oil ratio for a Scott Atwater 16

[Pete]

While this probably will not address the original question posed here is a 1978 article by Gordan Jennings 2 cycle motorcycle expert. Although the article relates to air cooled 2 cycle race engines the discussion is valid for water cooled 2 cycle engines and how 2 cycle lubrication works on the innards. No flaming please as the environment was not addressed in this article which I agree is important, just oil ratios discussed. In my race outboards at sustained 7000+ rpm I use more oil as Gordan indicates in needed. In my service engines I use less (factory recommendation) since rpm operation is much different.

http://edj.net/2stroke/jennings/oilpremix.pdf

Mercury did extensive tests during their many hours of outboard running at Lake X Fla and the affect on water quality with the oils they were using. The results reported were no measurable change. Don’t know what oil ratio Merc used in their testing and I have never seen the report, would like to read it. I read somewhere that during their non stop 50,000 mile endurance testing they used much more premix oil than they recommended in their operators manual. I suppose they wanted to keep um running for the news. Yes today’s oils are better but the same lubrication principals still apply.

Everything eventually wears out even us.