ORIGINAL: NCIS
After run oil is a waste of time in my opinion. When you burn the remaining fuel out of your engine you don't have any fuel or nito left, just castrol and that is plenty to lube the engine and protect the bearings. I don't use synthetic oil. I have seen to many people fry their engines running 100% synthetic. Again this is just my opinion.
Gibbs
Gibbs, Castor will gum the works especially if the engine will be dormant for several months. In the Surpass II engine, the bearings are of two different metals. This alone can set up an electrolosis problem leading to corrosion. Glow fuel is mostly methyl alcohol, and by nature, this substance is hygroscophic (It attracts water) You need something that will remain liquid and will displace any moisture that you might incur. My advice is to use the marvel mystery oil with a light shot of type F automatic transmission fluid mixed in. A little goes a long way. Be sure to flush the engine prior to running again. Too much after run oil could lead to a nasty hydraulic problem when you spin the engine using an electric starter.
There are many different schools of thought surrounding the use of After run oil, but that one has worked well for me for years.
Bill, AMA 4720
WACO Brotherhood #1