"The Yami service manual for t
"The Yami service manual for that model calls for 86 octane (regular).
I look at it like this - if the engineers who designed it say it runs on regular, why waste the money for a higher octane.
In any event stay away from super (93 octane) - the octane is artificially created with a number of additives, some of which are downright BAD for outboard motors.
As Grant notes, all blends have ethanol. That means that your gas is old in as little as 2 weeks - no big deal for your car since it's usually run daily, but horrible for outboards where a tank of gas could last many weeks.
The easiest way to prevent old gas is run stablizer all the time (recommended by just about all the outboard mfgs currently).
Alternately, only buy enough gas for your particular usage so that you don't have gallons of "left over" getting old in the tank.
Plus, if not equipped, install a quality water separating filter in addition to whatever is on the engine. The ethanol attracts moisture which ulitmately separates causing water in the fuel...."