I have no scientific evidence to back this up and I don't feel like doing the math...But I do have 20 years of mowing with D and F engines.....An not one power head failure....
I run 24 to one. One pint to three gallons, not rocket science to mix. Very good quality marine TCW-3 oil.
Now, I understand the lean theory. However, my plugs come out rather on the wet, black side, which contradicts a lean running condition. Next time I mow, I am going to take a cylinder temp reading. I bet these things run way hot, so my thought is that, especially when you bog down in heavy grass like I often do, and the cooling air flow slows down, I personally feel better with a little extra lube.
I DO think 16:1 is too much for a needle bearing engine. If it had plain bearings, that would be different.
Increasing the jet size increases the flow rate, and vice versa. However, on 2-strokes, the amount of gasoline flowing will vary with the amount of oil added at the pre-mix stage (the oil and gasoline both must pass through the main jet). More oil passing through equates to less gasoline, which equals less cooling.
Again, not trying to cause a big argument...to each his own! (-:
