Changing prop?? Moving up in pitch

[natedog337]

Hey guys I have a 26 foot sweetwater pontoon with a yamaha f115. I'm getting about 27 mph with a Solas 4 blade 13 pitch prop. I was thinking of buying an extra to have and figured maybe I would purchase a 3 blade 15 pitch prop to give me a little more top end speed and higher cruising speed. My engine is rated wot 5000-6000 and I get 5900 at full wot now with my 4 blade prop. Just wondering opinions on switching to a 3 blade 15 pitch and what it will do for me as far as speed and wot . I'd like my wot to stay somewhere close and not exceed 6000

Thx as always for the good advice

 

[steelespike]

Re: Changing prop?? Moving up in pitch

Your speed is very respectable.with a reasonable 20% slip. Pontoon slip is always high.
Your rpm is ideal. Marine engines work very hard like they are pushing a boat uphill forever with no relief,
especially with a pontoon.
When you increase pitch your asking the motor to push the boat uphill in overdrive.
You reduce the ability to handle weight as well and will likely require a higher throttle setting to maintain speed.
Your motor will be happier being able to rev freely within its rpm rating.