Yes, my misinterpretation. I had thought all along you were wanting to use 40% of the total fuel mix to be castor oil. Sorry if I confused anyone else. I add 3 or 4 ounces of castor to each gallon of 18% all synthetic lube fuel for all my engines. I use Klotz Techniplate at 20% total for my ASP engines burning no nitro. Good luck with your OS engines I have 9 OS engines from .15 to .80, both plain bearing FP and LA to ball bearing engine FSR, SF, AX and and FX.

Sincerely,

Richard