"A piston seizure can only occur when something burns or scrapes away the oil film that exists between the piston and the cylinder wall. Understanding this, it's not hard to see why oils with exceptionally high film strengths are very desirable, and why maintaining a proper oil-presence is also desirable. Good quality oils can provide a film that stands up to the most intense heat and the pressure loads of a modern high output engine. Here again, we mention that “absolutely no oil” has a stronger film strength than castor based oils."
"Castor-based oils have been a favorite of high-performance tuners for more than a hundred years. In it’s most elemental form, it is the oil squeezed from Castor Beans and its not significantly different from the vile tasting stuff your grandmother used to cure constipation. That castor oil worked because it was, among other things, a pretty good lubricant. Guess what? It’ll make your engine go too! Today’s castor-based 2 cycle oils bring some extraordinary qualities to the table. Castor has by nature incredible film strength. That means it can resist tremendous pressure between 2 surfaces without being squeezed out and allowing the surfaces to touch. This is especially important in today’s highly stressed 2 cycle engines. The point of contact pressures on connecting rod bearings in particular are almost unimaginable at high RPMs. It’s the oil’s job to maintain a lubricating film on these surfaces as well as the main bearings, and the all-important piston-to-cylinder wall interface so that they never actually touch. Another of castor oil’s endearing qualities is what oil experts refer to as “wetting ability.”"
"So let’s see, castor oil “wets” very well, but it leaves a lot of carbon and gummy residue, you can’t run it when it’s cold out, and it tastes bed (trust me!). So why is it so popular with tuners and engine builders? Two words: IT WORKS. For consistently squeezing that last bit of performance out of your engine, it's pretty hard to beat castor oil as the lubricant in your fuel."
From these snippets of excerpts.
I am suitably convinced why I choose to run 25:1 Castor.