Here I go against the grain again. I think too much of my engines to run a real lean gas/oil ratio. I like a margin of safety. I run Amsoil Dominator (50:1) at 40:1 with 91 octane gas in all of my engines and have for years. No over heating, no ring sticking, no excess carbon build up and great compression. There is a little black residue that wipes off easily with a paper towel. This residue is completely unlike glow fuel in that it wipes off without using a cleaner.

When I've had a cylinder off I find that the carbon is relatively soft and a little oily. When I've lightly scraped it I'll find a few places where the thin carbon will actually flake off revealing shiny metal below. Some other places, especially toward the exhaust require a little more scraping. I think some people are afraid that carbon will build up until the piston starts hitting the top of the cylinder. This just doesn't happen if the carbon is a little oily and soft. It sloughs off and goes out the exhaust. The ring or rings have always been oily and loose in the grooves. There has been no sign of piston scuffing. I truly believe more oil is better.

As Elson (RC Bugman) has so clearly pointed out that pulling draggy nets with RC airplanes is about the hardest environment for any RC engine. The oil that he uses can be critical for engine longevity. However, this is not normally the case for our gasoline powered engines. Proper air cooling is as or more important than the oil that we use. Oil also carries some of the heat off unless you are running a real lean mixture. Excess heat build up is a prime function in ring sticking. It gets really simple here: Almost any brand of 2 cycle oil will work fine if you don't mix it too thin, don't set your needle valves too lean and provide adequate cooling.

The question is, how many ways can you say the same thing?