Force 150 prop?

Dwamp2006

Cadet
Joined
Jun 8, 2015
Messages
17
Need a new prop for my 92 trophy 2002WA. Right now I'm only getting 4200 rpms and about 22knts at WOT. Any suggestions on which one to go with? According to the book I should be able to achieve 5500 rpms and about 40knts but I'm no where near that.
 

Frank Acampora

Supreme Mariner
Joined
Jan 19, 2007
Messages
12,004
I an very suspicious of a 150 that can only turn 4200 RPM on a 20 foot hull.

Sometimes the cables hang up and the last couple of inches of travel on the control handle is very difficult, making you think you have full throttle when you do not. In the driveway, push the control handle to full throttle. Then go back and remove the hood. Check that the throttle stop is against the block. Next remove the carb covers and be certain the carbs are opening fully. Double check timing to be certain that it is at the requires 30 degrees before top dead center at wide open throttle.

Go back to the force forum and watch the video: Tutorial about synchronizing timing and carbs.

THEN, if everything is correct consider dropping several pitches. At 4200 RPM, if you are using a 19 pitch prop you would need to drop 4 pitches to a 13 X 15 prop giving you about 5,000 RPM. However not knowing what pitch prop you have currently it is not possible to recommend dropping pitch yet.

Upon further thought: Are you using a thru-hub exhaust prop? That engine is a dual exhaust model unless someone has changed the lower unit, Using a closed hub prop will lessen performance.
 
Last edited:

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Your present prop size may be near the base of the blades or under the prop nut.
 
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