The engine in question in one that calls for some castor, and may have a lapped iron/steel P/L rather than ABC since OS made both flavors for the FP's, and the OP is clearly someone who hasn't been around for decades in the hobby if they couldn't identify an FP and probably needs some fuel advice since there are many commercial fuels on the market capable of destroying this engine in the hands of a relative beginner.

That's why the discussion headed where it headed.