toddincharlotte
Junior Member
I've been using premium simply because before I got a chance to check out my owner's manual I assumed any engine with a 12.4:1 compression (or whatever it is) would take premium... Then I saw the manual but I'm hesitant to "downgrade"... Eeehhhhh...
"Your Yamaha engine has been designed to use regular unleaded gasoline with a research octane number of 91 or higher. If knocking (or pinging) occurs, use a gasoline of a different brand or premium unleaded fuel. Use of unleaded fuel will extend spark plug life and reduce maintenance costs."
The manual is kind of confusing but I interpret this as "use Premium". I take their meaning on "regular unleaded gasoline" meaning pump gas vs. racing fuel.