Reply To: Fuel oil ratio

[Don]

While Tubs is certainly correct, oil quality has improved greatly over the years, I’ll stick with the theory he mentioned when it comes to plain crank/rod bushing engines, at least on any of my nicer engines that don’t get that much use. While the environmental factor is one that I selfishly have not considered, it is amazing how little these engines smoke at 16:1 when properly tuned…And, the 1960 models have a thermostat which will heat the engine up a bit more, reducing smoke even more.