• All high performance air-cooled engines should have the highest octane you can find. Octane helps prevent spark knock that can easily damage your engine.
• As great as the appeal of non-ethanol fuel may be, I'm not sure you get the same cleaning agents as in the regular "high test" fuels. True, if you're going to ride intermittently over (say for instance) the winter, then non-ethanol would be highly preferable. But during spring and summer when riding time is plentiful, I opt for the less expensive name-brand fuel with the built-in cleaning agents. This is because all fuels leave scuzz in the carburetors, which ultimately needs removal. It just so happens that the ethanol laden fuels simply start to leave deposits earlier.
So as long as fuel is moving through the system, I'd rather have the standard high octane fuel.