120 force 1998 prop

[tomcatcain]

Just bought a 19 ft trophy 1998 model 1903CC has a 1998 120 hp force motor.Need a new prop but cannot read numbers on old one.Any one can recomend size an pitch to use,motor wot rpm by book 5250. Thanks

 

[Silvertip]

Re: 120 force 1998 prop

There is no standard prop for any engine. Since you don't know what you had before, what wide open throttle RPM was with that prop, or what the maximum speed was at that rpm, we have very little to go on. The 5250 RPM WOT you reference is the target rpm with whatever prop you buy. Too much pitch will prevent reaching that rpm. Too little pitch puts rpm over the target. 13-1/4 x 19 pitch is in the middle of the pitch range for that motor so thats a start. If the hull is relatively efficient perhaps a 21 pitch will be acceptable. Here is a prop calculator and the second link is the iBoats prop store.<br /> http://www.csgnetwork.com/marinepropcalc.html <br /> http://www.boat-props.com/propellers/s#sterndrive