I have a 1975 OS Max 15 that I want to use for a trainer. I say it's a 1975 because I looked on the O.S. website and that's what the website shows. I can't find any documentation for the engine, so I'm asking here. What would be the best fuel to use on this engine? Does it need the higher castor content, or did the '75 OS engines run okay on mixed castor and synthetic? Also, what is the best plug for this engine?
I'm going to put this on a SIG Buster for a trainer, so I want it to be slower and controllable. I'm thinking of using an 8x3 or 8x4. What's the best recommendation from the experts here?
Mark