Proping help ...

[NWwalleye]

I just recently purchased a brand new 2014 F90 LA
The motor is installed on my 2000 Lund 1775 Pro-V tiller ..

The factory 17" prop gets my boat out of the hole relatively good with only me in the boat ... it reached 5800-5900 RPM and speeds of 36 - 37 MPH @ WOT ..

But, when I load a couple of other guys and their gear..
The hole shot is poorer and the RPM has dropped by 100 RPM and the speed is running 34 -35 MPH..

Is this a normal ???
Would a different type prop or pitch work better ?

The boat had a F75 on it before the motor swap ..
There is a significant difference between the 2 motors.
But, I guess I had expected more speed ...

Any suggestions on size of props or other brand, would be greatly appreciated..

Thanks in advance for any and all help ..

[DennisG01]

Assuming you're "trimming up" properly, you have a little more to go in terms of MAX RPM. So, yes, you could step down to a 15" prop to get better performance when loaded up. But based on standard practices, your current prop is probably the "normally" recommended one. You "might" over rev it when you're light (with the smaller wheel), but you can control that through throttle and trim use. You may or may not gain any speed, though. A smaller prop equals less speed at the same RPM, but you will gain some RPM so that will help to offset it.

There really is no "one best prop", regardless of what you might here. The best place to ask for recommendations, though, is going to be from people who own similar boats to you. See if there's a forum for your model. A 90HP on one particular hull design will perform differently on a another hull design. A "bass boat" for example, will fly with a 90HP.