I was asking about expected mileage back awhile.

It went something like this. Son bought a used Honda 10 hp 4 stroke to
replace the 18 hp 2 stroke Johnson. Took a day of enlarging the motor well
and half a day of tuning the engine but I have to say it turned out perfect.
Motor is so quiet you can actually have a conversation at full throttle.
Made a loop around Alameda Island/Coast Guard Station and back, low bridge
makes it so you have to double back. So little gas was used from the 3
gallon tank that I couldn't even guess what the mileage was. Clean, no oil
slicks, not a lot of fumes in the air, seems very eco friendly.

Motor does seem to have a bit of vibration that is transferred to the boat.
I'm not sure if it is motor or prop or some odd combination of harmonics but
it isn't bad enough to worry me. The motor makes its hp at fairly low RPMs
and is well matched to the prop so I am changing to judging speed by how
fast the boat is moving rather then how loud the engine is screaming!

Thx for the helpful comments.
Rick
--
"The basic tool for the manipulation of reality is the
manipulation of words. If you can control the meaning of words,
you can control the people who must use the words."
(Philip K.Dick)