Posts: 3480
Location: Elk River, Minnesota | Hi Dave,
Depending on the water outlet, it might just be a hose that comes through a rubber grommet, and it might just need to get pulled out a little more.
Steve Worrall is correct in that when you increase diameter, you will reduce RPM's... Here are rough estimates of what happens:
Every 1/4" change in diameter will be a change of roughly 100 RPM's. So...if you go up 1" in diameter, be expecting a reduction of roughly 400 RPM's on your engine.
Likewise, (as I believe Steve Worrall mentioned earlier) that a 1" change in pitch will change your RPM's anywhere from 100 to 150 RPM's. So...going up from a 19 to a 21 pitch prop could reduce your RPM's by something like 200 - 300 RPM's.
So...if you go 14 x 21, you would roughly see a decrease of roughly 600 to 700 RPM's... It might be what you need, depending on where your RPM's are currently.
The wings are not a negative thing for many boats. They are designed to help under-powered boats stay on plane at lower speeds because the power is not there for the engine to do it alone. The wings provide stern lift and if the fin is in the water, the ability to trim the boat a bit better. With your rig, you are max on HP, so the right prop will bring your boat alive.
With your combination, you should be really close to, if not over 40mph...
Steve |
