Originally Posted by WayneC
Speak more of the use of Castor oil. Are we talking about the same stuff you get at the
pharmacy or such places? Or is there 'engine grade' oil at the auto parts store? How much to use? Does it gum up the works? Etc., etc., etc.
If you have a good hobby shop near you, especially one that specializes in model airplanes, they should carry Castor oil compatible with fuel. Don't buy model airplane fuel with Castor, just the oil. As Pablo said, Sig, is one of the major suppliers and a popular brand with the model airplane folks.