3.0l 140 hp omc stringer. Prop questions

[Scottyitsk]

Hello everyone.

1985 ebbtide montego 3.0l omc stringer drive.. 17ft ski boat

With a 13 3/8 x 17.... 3 blade SS prop... the boat seems to take a good bit to get planing... the hull lift is pretty crazy with two people sitting by helm of boat. Once planing... the boat runs about 40 MPh at 4700 rpm.

Is this prop causing the planing issue? Tilt all the way down.

Boat stringers, foam, and transom replaced 5 years ago

 

[steelespike]

A stainless prop with bow lift may struggle with planning. 40 at 4700 indicates about 0 slip.12% is more typical.
Is the speed by gps ?

 

[southkogs]

My old Comoro was kinda' like that ... 2,000# bein' pushed by 140 (in my case 165) ponies. It just took a little get up outta' the water.

Tilt is all down, but do you have selectrim?

 

[Scottyitsk]

no select trim, just tilt.

And yes, that is gps verified.. runs great... just struggles to plain under half throttle.... takes 3/4 to full throttle to get on plane