New F300 octane

[pbaygrady]

Fuel available in my area is all 87 octane and I know Yamaha recommends 89 or higher on the Offshore F300. Is there a recommended octane boost by Yamaha? I normally used Startron to combat ethanol issues with good luck, but don't think it does anything to the octane level.
Thanks in advance.

[boats.net]

Best to call Yamaha directly and ask them before mixing a lott of different additives in gas.