I'll be running a new rig this year, a Lund Fisherman 1800 with a Mercury
114 4-stroke. I'm curious about whether I should run 87 or 89 octane. My
old Yamaha 2-stroke ran much better with 89. On the other hand, I've never
noticed a significant difference on 4-stroke motors in my cars.

Any input?

Thanks,

dm