Prop Question.

The Cintas Guy

Recruit
Joined
Aug 3, 2008
Messages
5
I have a Stratos XL185 with a OMC 4.3 and Cobra outdrive. It has what seems to an 18 pitch prop on it. It's turning 4800 rpms at 40 mph, but the engine will rev well over 5000 rpm if you let it. The prop is an 18 pitch SS prop. It would seem somebody had it reowrked at one time. I've been keeping the rpms in the 4200-4400 range is about 35 mph or so. Do I need a 21 pitch or maybe even a 23pitch. The boat comes out of the water like a champ planes in seconds, I assume I will kiss that goodbye correct? Thanks in advance for your help.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: Prop Question.

A 1" increase in pitch will reduce rpm by ABOUT 200 rpm. and so on.
If the motor is in good health you can run it long enough to get a max rpm.
with a light load.You should stick with the stainless as going to aluminum
introduces more variables make rpm/performance a bit of a gamble.
A Turning point Hustler Al. prop will run close to the stainless if your
short of throw away money.
 

The Cintas Guy

Recruit
Joined
Aug 3, 2008
Messages
5
Re: Prop Question.

A 1" increase in pitch will reduce rpm by ABOUT 200 rpm. and so on.
If the motor is in good health you can run it long enough to get a max rpm.
with a light load.You should stick with the stainless as going to aluminum
introduces more variables make rpm/performance a bit of a gamble.
A Turning point Hustler Al. prop will run close to the stainless if your
short of throw away money.

So you agree a new prop is needed? The motor runs strong, I would just rather not turn it that hard. I will run it this week and see where it tops out at. RPM wise.
 
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