Pitch and diameter

logart00

Cadet
Joined
Jul 22, 2006
Messages
12
I have a 13-3/4 x 15 prop right now that is in need of replacement. I would like more RPM, since the boat has a hard time planing when I have more than 3 people on it (which is often).

I see a 13-3/4 x 13 prop listed in the iboats.com prop selector. Am I supposed to keep the same diameter and just change the pitch to get better planing and hole shot, or should the diamter go down as well?
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: Pitch and diameter

Diameter in aluminum usually goes up with a pitch decrease...some stay the same.
What RPM are you running with a load?
 

logart00

Cadet
Joined
Jul 22, 2006
Messages
12
Re: Pitch and diameter

I am getting ready to order a tiny-tach, so I don't know for sure what the RPM is. Guess I should check that first before buying a new prop?
 

Crownie2

Petty Officer 1st Class
Joined
Jul 26, 2006
Messages
378
Re: Pitch and diameter

logart00 said:
I am getting ready to order a tiny-tach, so I don't know for sure what the RPM is. Guess I should check that first before buying a new prop?

Yes - you need to know what your max RPM's are before playing around too much.

Bob
 
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