One note - to much oil is not really bad. I run my Poulan on 1:50 oil and it run very dry. I mean when it stopped I hardly felt much compression. After running on 1:25 the compression felt quite well to the point where the flipping the prop was like flipping, not turning. Lower oil content didn't improve rpm at all (or maybe it lowered it a little). Of course more oil in = more oil out -> dirty plane, but I would rather clean the plane than have a 'dry' squicky feel on the prop. With conversion engines I would stay with at least 3% oil (I even tried 6% and engine run fine).

The other thing that is different from a 'glow' ennges, is that whacker conversions don't need to be run rich. If you have enough oil for lubrication the engine can be tuned for max rpm. They don't need to be cooled by the oil. Fins on the cylinder are big enough to run them just fine. They were designed to run on hot fuel (gasoline) and the engine runs enclosed in the plastic box (trimmer or chain saw head) without much cooling air around.

This is just on the side note.

RysiuM