hallo!
Why bother with Klotz oil when you could get racing oil from the French Motul company( there must be a Motul retailer in the USA).
Motul makes racing oil for motorcycles and cars, they also make an oil specially for glowengines,this is called "Micro"!
Many flyers all around Europe uses this oil and so do I.
15% oil is what Motul recommends!!!!!!! I have used it for two years and in both fourstrokes and in small and big twostrokes ( Cox 0.049 - MVVS 1.50) with great satisfaction . It does not produce any carbon inside the engine and throttle respons improves.
I was I great advocate of castor oil for more than 25 years ,but since I tried the Motul "Micro oil" all syntetic oil two years ago I´m hooked..........


Regards!
Jan K
Sweden