2008 maxum 1800 sr3 4.3 190hp prop

[madman2021]

Need a prop for my new ski boat. Still has the factory aluminum prop on it. Getting 5400 rpms(way to high needs to be 4800-5000 rpms) 49.6 mph. Hole shot is terrible, falls off plane under 27 mph, can't trim up at all without severe porpoising. Won't pull me up on a wakeboard(275lbs). Use to run a high five on my 4 cylinder mercruiser and it yanked me out the water easily. Can't get the numbers off the prop previous owner put bottom paint on the prop and the entire outdrive.

 

[SkiDad]

you don't saw what prop you have but you probably need to look at something in 4 blades.

 

[steelespike]

Your prop numbers should appear under the prop nut.Other numbers near the base of the blades.
Make believe your life depends on them.(paint remover perhaps)
Is the 49.9 @ 5400?Is the speed by gps? Is 49.9 lightly loaded?
Do you know your gear ratio?
Guessing your prop size using 1.81 ratio 5400 at 49.9 I get approximately 21"
Using 1.61 ratio I get about 19" This is not a good way to check prop size.
Both these prop sizes should pull a skier. and stay on plane normally though certain designs may not.
From your performance I would say it is unlikely the prop is factory recommended.
Not unusual for a seller to remove their best prop a substitute a prop that simply fits.
What is the diameter?measure from tip of a blade to the center of the bore and double it.

 

[Bondo]

Need a prop for my new ski boat. Still has the factory aluminum prop on it. Getting 5400 rpms(way to high needs to be 4800-5000 rpms) 49.6 mph. Hole shot is terrible, falls off plane under 27 mph, can't trim up at all without severe porpoising. Won't pull me up on a wakeboard(275lbs). Use to run a high five on my 4 cylinder mercruiser and it yanked me out the water easily. Can't get the numbers off the prop previous owner put bottom paint on the prop and the entire outdrive.

Ayuh,..... So sand, scrape the paint off,.....

Without the size, yer question has No answer,....