# prop help request



## The Rodfather (Dec 9, 2016)

So i have a 16ft salt marsh with a merc 30hp. Right now it has a 4 blade aluminum 9.3" diameter and 9.5 pitch. At WOT i hit the re ev limiter at 25 to 26 mph, and the torque is amazing. Although im in the market for a new prop since mine is dinged. I want more top end and wouldnt mind sacrificing a bit of torque. I have in mind what to get after some advice but would like a second opinion from the forum. I got recommended a 10 pitch, 3 blade ss prop.


----------



## LowHydrogen (Dec 31, 2015)

Welcome to the forum.
Keep in mind that you're already hitting your rev limiter and the 3 blade is going to turn up even higher than the 4, you may need a bit more pitch with the 3. You are dropping a blade but only adding .5 pitch.

There are some really knowledgeable folks here that will be more familiar with that motor.

They're going to want to know the year of your motor, 2 or 4 stroke, what your boat weighs with you and your avg load, and what your rpms are. If you don't know that, knowing what the rev limiter is set at will help them also.

Good luck.


----------



## The Rodfather (Dec 9, 2016)

Thanka for the response the boatvweight 350 dry plus 2 24 class batteries a trolling motor and 2 coolers plus a few rods and tackle box. Im going tobsay no more than 550. My engine is a 2016 4 stroke. And my 1st opinion was with ken from prop gods.


----------



## LowHydrogen (Dec 31, 2015)

Oh, If that is who gave the opinion, go with it. Lol you likely won't find a better opinion than that. You're in good hands that guy is well known and highly respected.


----------



## RunningOnEmpty (Jun 20, 2015)

The Powertech sra3 is really good prop. With a boat that sized a 10 pitch would be my starting point. The sra3 10p powertech has heavy cupping so it tends to perform more like an 11p. It also performs well jacked up for running skinny.


----------



## Vertigo (Jun 3, 2012)

The fact of the matter is that to find just the right prop, you're going to have to experiment. I've run two of the same pitch and design Powertech props on the same boat and gotten entirely different results. That tells me that there's more than a little variance in new props right out of the box. Start with the 10 pitch Powertech, but be prepared to swap it out if it doesn't meet your expectations.


----------



## The Rodfather (Dec 9, 2016)

So i went out the other day super light with no TM or battery and just 2 fly rods and topped out at 27mph but hit the rev limiter very fast and the motor was screaming high rpms. Now if i decided to keep my same prop which is a 9.3 diameter with 9.5 pitch. But just raise the pitch to 11 i know ill take care of the over rev issue but will i get more top end ?


----------



## Steve_Mevers (Feb 8, 2013)

The Rodfather said:


> So i went out the other day super light with no TM or battery and just 2 fly rods and topped out at 27mph but hit the rev limiter very fast and the motor was screaming high rpms. Now if i decided to keep my same prop which is a 9.3 diameter with 9.5 pitch. But just raise the pitch to 11 i know ill take care of the over rev issue but will i get more top end ?


My understanding is that the motor needs to top out at the recommended top RPM under load, without a RPM gauge it makes it more difficult to figure out. Since you are hitting the rev limiter, if it was my boat I would take the prop down to a prop shop and have them increase the pitch to an 11.5. You should pick up more speed because it will drop your RPM down to where it needs to be to stop the rev limiter from kicking in. The guys at Powertech are very helpful.


----------



## Preston904 (Sep 9, 2016)

get a tach for sure. I thought i was turning 6500+ rpms on mine because i ran 31 with a 11.25 pitch and i assumed a 5% slip. turns out I was only a 2% slip and it put me at 5980 which is perfect.


----------



## The Rodfather (Dec 9, 2016)

So i ended up getting a blackmax aluminum 9.5 inch x 11 pitch 3 blade prop. The motor no longer over revs and im now getting 27mph fully loaded with 4 people. And getting 30mph with 2 people. Very happy with the performance and didnt lose much torque from my previous 4 blade.


----------

