Aluminum Vs Stainless prop ?

Hi all,

New guy here

I picked up a 2010 Yamaha F90 on a G3 V172 (weight about 1,500lbs) it came with a Stainless K16 13.5x16 prop. G3 factory says the stock prop should be a Yamaha 68V-45941-00-00 Al 13.5x17.

I understand stainless is thinner than Aluminum
Does the different material affect the pitch performance of the prop?
Would I select a lower or higher pitch when changing from AL to Stainless?

Re: Aluminum Vs Stainless prop ?

When switching from aluminum to SS, it's recommended to reduce an inch of pitch to maintain rpm.

Those two props are right on the money; the SS is one inch less than the aluminum.

The SS blades are thinner with more cup, and much stronger (less flexing), resulting in greater thrust and holding. The additional cup is the reason to reduce the pitch, as additional cupping is like adding pitch to a prop.

Re: Aluminum Vs Stainless prop ?

jestor68

Thanks for the response, it's greatly appreciated

Re: Aluminum Vs Stainless prop ?

And the thinner blades of the SS are more efficient. Case in point, take a Turning Point Hustler in aluminum with all the amenities of a SS prop except for the blade thickness (due to the material difference) and the performance is different from a SS with the latter allowing you to turn higher rpms for all other things being identical....and with that said, that means a mile or two more mph. I have both.

Other thing with SS is that you don't have to take your prop back to the prop shop on Monday after a weekend outing like you do with an alum if you have any kind of under water hazards, including 2" saplings that used to devour the alum prop on my 125 Johnny back in '72.

Mark

Re: Aluminum Vs Stainless prop ?

It's nice to have a SS and aluminum prop on hand. I run SS in our lakes because the water level is consistent and I know where the hazards are located. I run aluminum when I'm over on the Gulf Coast. SS does give like aluminum as everyone has said. If you hit a rock or decent log the aluminum prop will give or break. SS hits something that won't move you can lose you lower leg or outdrive. Just know your water and SS props are great!!

Re: Aluminum Vs Stainless prop ?

know your waters good s. s. props have made my buddy rich .though the hubs are suppose to cushin the effects of a hit you would be amased at the motors and damage ive seen from prop strikes when i visit the shop.that being said i know my waters and have used stainless and have never hit anything period for about 30 odd years.

Re: Aluminum Vs Stainless prop ?

Stainless will cut through bark or branches that might damage an aluminum prop. They also weigh more and act like a bit of a flywheel that helps reduce engine vibration. People always say that stainless will ruin the leg or driveline but I have never met anyone who has had that happen to them. I have met people that have ruined there outdrives but that was through impact, not prop impact.

Re: Aluminum Vs Stainless prop ?

Thanks all

I believe I will pickup the stock Yamaha prop as a back up for the existing SS prop
My waters are full of floating trees / huge logs / etc during the spring run off
Water depths are typically less than 25ft where we fish