ORIGINAL: iraqvet
I'm running a hand-me-down OS.40FP (about 15 years old but with low hours) on my Tower 40 trainer swinging a 10x6 Master Airscrew glass-filled nylon prop on 15% Cool fuel.
IraqVet,
Why in the world would you want to punish this engine with CruelPower???
This engine has an ABN P+L set, which according to [link=http://www.osengines.com/faq/product-faq.html#q2]OS' Q&A[/link], will run much better, on fuel that contains a lot of castor oil (CP contains none at all).
Also, this engine has a bronze bushing bearing, that also requires castor oil to live long...
The CP fuel may keep your plane a bit cleaner (but you do have to clean it anyway),
but it will half the engine's life, if not more than that.
Morgan themselves recommend their own '[link=http://www.morganfuel.com/omega_main.htm]Omega[/link]' fuels for ABC/ABN engine;
not their CoolPower.