Octane level?

[1985 90HP Yamaha]

I have a 1985 Yamaha 90hp ETLK...can someone tell me what octane Level fuel I should be running?

Mark.

[Ken]

Mark,
My guess would be 87 octane - I don't believe that 85 90 hp is a high compression engine. The owners manual would tell you - go to www.yamahapubs.com if you don't have one and see if it is still available - use to, you could download owners manuals for free.
Good luck,
Ken K