20 ft lowes

[Triphammer]

Hi All,
I'm running a 13.5 x 15 three blade on an 87 125 Force. powering an 87 Lowes Fish N Fun, 20 ft. At 3500, about 3/4 throttle I'm running 24 (GPS). I haven't had it up to WOT as the lake was choppy & this was my first outing on the rebuilt boat. If I'm doing the math right I should be running 28 MPH @ zero slip , so is the 4 MPH, about 20% acceptable slip?

 

[steelespike]

Re: 20 ft lowes

Actually I come up with about 16%,I think very good for the reduced rpm. 5250 at 10% slip is about 38 mph.
This disregards weight and hull characteristics

 

[Triphammer]

Re: 20 ft lowes

Great, thanks. The prop that came on the motor was shot & unmarked so I picked one based on othose listed as OEM & what was on Ebay. So is 10% +/- considered normal slip?

 

[steelespike]

Re: 20 ft lowes

Typical slip on 17 to 20' boats like your size would be 6 to 12% I picked 10% just to figure wot speed estimate.
Slip may vary slightly over or under the numbers and still be considered acceptable.