Those running 115's on a 20

[McGillicuddy]

mrobertson,
Nice score. Yeah, I stay on plane easily to about 15mph. I will be putting trim tabs on as I seem to lean to port a wee bit when running NW.

The gear ratio on the Yammie is also 2:1. For me a 17P was ok but when I went to a 15P every aspect of performance improved. Including top speed and economy. I believe you'll get better economy with that Yamaha - probably over 3 mpg at 4000rpm.

I would love to see what that engine does with the same prop I use.

You might consider a 4 blade semi-cleaver prop as you'll have more weight aft in the cc. Check out PowerTechs SCD4. That Yammie IS a proven motor. If you can, get the Yammie controls, everyone claims they're great.