engine rpm vs weight and prop pitch

ooootis

Petty Officer 3rd Class
Joined
Apr 26, 2003
Messages
80
just wondering bout weight of my boat, 1990 Performer CC with twin OMC 2.0 liter Seadrives. <br />I dont have a clue how much this boat weighs but it holds 215 gals of gas. WOT is 5000 - 5100 rpm @ 49-54 MPH. As expected the mph varies with weight. Should the rpm vary with weight also. Only variances with old boat was 40 gals of gas not enough to worry bout plus it was an inboard so I really dont have a clue here, I guess what I'm try to get at should I worry bout repropping this boat. Props are 14.5 X 21. Manual say max horsepower @ 5500. Have heard 6000 for max but its not in print in the OMC manual.<br />thanks in adv.
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: engine rpm vs weight and prop pitch

If engines are mounted at optimal height on transom I would drop back to 19" pitch props.
 

ooootis

Petty Officer 3rd Class
Joined
Apr 26, 2003
Messages
80
Re: engine rpm vs weight and prop pitch

hey OB as far as i know they are mounted on OE transom plates and are no adjustable no cut out in transom.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: engine rpm vs weight and prop pitch

You cannot (easily) change the X dimension on Sea Drives. They must be treated as stern drives in that sence. I would do as OB suggests and try a pair of 19's. The loopers are fairly forgiving but the dont liked to be lugged.<br /><br />Good luck!
 
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