RE: Too much oil.
A lot of the guys I know on the circuit with the bigger 2 and 4 stroke larger engines from 20cc to 50cc glow best I can tell are like me mostly using synthetic oil ester type like EDL @10% to 12% and no castor with zero nitro or maybe 10% for the 4 strokes and lots of them even use that brew on well run in smaller 40 sized or even smaller motors
I have heard of some guys even going to 6% synthetic oil Ester Family oil type like EDL with no Castor and I will try to copy this trend as at local import prices of 65 Euros a UK gallon for EDL (~ $110 a USA gallon ) 6% oil can save me a lot over 12% oil
(best I can tell the USA oil is PAG family oil type which cant go so low in oil content as the Ester family oil types )
Really the less oil the more power in the fuel and lower cost and with tweaking of jets or similar I am sure the rougher running and lower RPM from lower oil content issues can be sorted out and engine costs are dropping so I figure I can handle a small extra increase in wear rates if necessary from engines if the oil content can be halfed to 6%
Balsaeater