should I leave well enough alone

[Toyelectroman]

I think I might be over propped but barely, currently running an outboard 115 Mercury command thrust on a pontoon with a 4 blade aluminum 15x17 prop and at WOT I am at 5280 RPM's. Per Mercury the RPM range at WOT is between 5000 - 6000. Should I try going down in pitch or am I good were I am at?

 

[Sea Rider]

Will depend entirely on your toon current load, with stated wot rpm achieved, going down at least 2 pitch will bump wot rpm way more towards the middle to max wot rpm range, by how much excatly ? only a wot test will determine so.

Happy Boating

 

[porscheguy]

I’d come down probably 2” in pitch. It’s better to be at or near the top of the rpm range versus at the bottom. You may find you gain enough rpm to actually increase your top speed and overall performance.

 

[Toyelectroman]

Looks like i was wrong on my prop, currently i have a nemesis 14x17 4 blade not 15x17. I was looking at amita 4 blade that is 14.75x15. Would that increase my rpms?

 

[harringtondav]

Looks like i was wrong on my prop, currently i have a nemesis 14x17 4 blade not 15x17. I was looking at amita 4 blade that is 14.75x15. Would that increase my rpms?

Maybe. But the increased prop diameter will offset some the pitch reduction. For certain a 14x15P anything will increase WOT rpm, if that is what you really want. "Should I try going down in pitch or am I good were I am at?" That is for you to answer. Do you have specific concerns about your boats performance?

 

[Texasmark]

Agree you aren't running a 15" dia prop on a 115 engine (which has the 4" dia gearbox housing). Getting a 14" dia on there is squeaky....if you have much pitch your trim tab would get whacked........I have a 14 that I ran on the 4" box but most props for that box are 13+.

I always run my engines maxed out in RPMs at the throttle setting I use most (WOT grin), especially 2 strokers.....you didn't say if yours was or wasn't......with 6000 as your upper limit it's probably a 4 since most 2 strokers list 5500 as the upper limit.

If you are where you are with max load and don't max load regularly I'd stay. If not, do as you suggest. My opinion.