Continuing the thread about the Aquasport 170, I've been thinking about the re-power option, though it's really quite a ways off. What kind of mileage do you get with the 115 Yammie? Also, what kind of top speed? What pitch prop?
I took my carbs apart this weekend (had to, got epoxy shavings in the fuel line during starter replacement), and discovered one spark plug had electrodes completely closed. Fixed the plug and ran the boat yesterday, and it's never run better (I bought from a friend, so I've fished this boat for about 5 years). Must've been doing 50 MPH at WOT.
Hey, Eddie Joe
Moderators: bman, Chalk, Tom Keels
, but ain't it great when your boat runs like it should 
.LF:
The 115 Yam gets about 3-4 mpg, depending on conditions. Calm is best and not going into the wind. The 170 Aquasport has such a high bow profile that I actually believe it cuts down on mpg/speed. You can really tell when you are heading into a brisk wind. Trimmed up, the boat will go from 42-44 mph. I can't recall the prop pitch, but it might go faster with a different prop. Usually, 25-30 mph and 3500-4000 rpm is just right for me, so top end doesn't matter. That is also the most efficient rpm for mileage.
The 115 4 cyl Yam is much heavier than the 90 hp 3cyl, so top speed with each may work out to be the same, although I think I can push a heavier load onto plane with the 115. With our boat, I believe you should stick with a 2 cycle, because of weight.
EJ
The 115 Yam gets about 3-4 mpg, depending on conditions. Calm is best and not going into the wind. The 170 Aquasport has such a high bow profile that I actually believe it cuts down on mpg/speed. You can really tell when you are heading into a brisk wind. Trimmed up, the boat will go from 42-44 mph. I can't recall the prop pitch, but it might go faster with a different prop. Usually, 25-30 mph and 3500-4000 rpm is just right for me, so top end doesn't matter. That is also the most efficient rpm for mileage.
The 115 4 cyl Yam is much heavier than the 90 hp 3cyl, so top speed with each may work out to be the same, although I think I can push a heavier load onto plane with the 115. With our boat, I believe you should stick with a 2 cycle, because of weight.
EJ