O.e. Prop size

[Tim Bell]

i'M LOOKING FOR A STARTING POINT TO CHOOSE A STAINLESS PROP SIZE AND HAVE NO IDEA WHAT IT CAME WITH.
1991 RINKER CAPTIVA OPEN BOW 20.5'
305 CU. IN. 2 BBL. CARB. MERCRUISER 1.65 GEAR
WANTING FOR GENERAL USE AND LITE TOWING (KIDS)

TIM

 

[MBAKER]

Re: O.e. Prop size

Im sure someone will have more technical but from recent expericen Id say a 19 pitch would work for you, or 17 for more bottom end. In a similar sized maxum with 305 and 1.47 drive it came with a 19 but we used a 17 cause we were usually pretty heavy and it helped with towing. Thats all assuming you engine is in good shape and good tune.

 

[Tim Bell]

Re: O.e. Prop size

BOAT HAD A 14.5" X 19 PITCH AND CRANKED 5000 RPM. THOUGHT THAT WAS A LITTLE MUCH. gOING TO TRY A 21 PITCH.

 

[MBAKER]

Re: O.e. Prop size

yeah that sounds about right, considering you have more gear ratio in the drive than i have. If you had your normal load in the boat 5000 to me doesnt seem bad unless you want all out speed. You can always pull the throttle back a little to keep from over revving, and have a little low end power for towing.

Was the 19 pitch aluminum? Its hard to compare changing props how one will act compared to hte other of a different family, brand etc. I woul almost guess a stainless 19 will not turn the revs an aluminum will but it all varies.

 

[Tim Bell]

Re: O.e. Prop size

The 19 aluminum would slip just before it would start to plane.

 

[RogersJetboat454]

Re: O.e. Prop size

If you were to consider switching to an aluminum 4 blade 19 pitch, it will probably drop your WOT RPMs down into a more friendly territory, plus you will have a bit more ummph for towing.