Stainless prop advice

[MAP]

I have a 22' Avalon with a 115FS Yamaha. I am considering a stainless prop and keeping the aluminum one for a spare. I am not necessarily looking for a performance gain but if it happened I won't complain. I figure having a spare on board is a good thing and the stainless seems it would be more durable.

I need some advice on what brand of prop is good and what if any differences I will see over the aluminum one.

I am not sure of the diameter or pitch of my current prop but it came with the motor. Currently WOT is about 5600 rpm and I get 23KTs GPS with 3 or 4 people on board. We usually cruise at about 3800rpm and 13kts.

Thanks

[BassFrequency]

I have a 22' Avalon with a 115FS Yamaha. I am considering a stainless prop and keeping the aluminum one for a spare. I am not necessarily looking for a performance gain but if it happened I won't complain. I figure having a spare on board is a good thing and the stainless seems it would be more durable.

I need some advice on what brand of prop is good and what if any differences I will see over the aluminum one.

I am not sure of the diameter or pitch of my current prop but it came with the motor. Currently WOT is about 5600 rpm and I get 23KTs GPS with 3 or 4 people on board. We usually cruise at about 3800rpm and 13kts.

Thanks

i run a 13p stainless on the 60 evinrude and ive noticed better performance and faster blowout recovery at high trim or sharp turns. I have a aluminum spare of the same pitch and there is a big difference.

[Heatman]

I tried to go to a stainless prop and it didn't work out for me. I have a 90 hp and bought the same exact size and pitch as my aluminum one. It was however a different brand. My Rpm's went for 5,400 which was perfect to 4,500 , way to low. So be cautious on what you get as they aren't cheap. I ended up selling my to a member on here dahogman and fortunately it worked out for him.

Best advice would be if you could find a marina nearby that may work with you and allow you to try a couple different ones out.

[dockholiday]

Thinking 13 to 14p might be right. Agree with heat, need to get a dealer or prop shop to work with you finding the right prop. There is one downside, they won't bend if you hit an obstruction like the alum will.
doc

[jimrs]

"There is one downside, they won't bend if you hit an obstruction like the alum will."

That to me is the upside, I don't want my props to bend if I hit something. Most things you hit won't affect a SS prop but will bend the Hell out of a alum. I have run SS props for over 30 years and have never had one hurt or hurt anything else on the motor. I have hit a lot of stumps and stuff with no problems. Some of my boats would do over 50 m.p.h. and I have hit things at those speeds and not a problem. I hate alum props they are usless once you hit something.

[LTB Racing]

"There is one downside, they won't bend if you hit an obstruction like the alum will."

That to me is the upside, I don't want my props to bend if I hit something. Most things you hit won't affect a SS prop but will bend the Hell out of a alum. I have run SS props for over 30 years and have never had one hurt or hurt anything else on the motor. I have hit a lot of stumps and stuff with no problems. Some of my boats would do over 50 m.p.h. and I have hit things at those speeds and not a problem. I hate alum props they are usless once you hit something.

I agree completely....bottom line if ya hit something so hard that you'll break/bend a SS prop... chances are good that you're going to damage the lower unit anyway. One brush w/a sandy bottom and it's time to recondition the aluminum which is a pain and gets expensive quick....Alum's are great to keep in the boat as a spare.
One thing you may notice with SS props is more prop chatter or growling at slow idle....this is normal.

[slingshot]

You’ll need to know some info about your motor before you do the switch:

1. What is your engine’s max RPM? (yours is probably 6000 rpm if your rev limiter is letting you get to 5600 now)
2. What is your current prop pitch?

As a general rule you’ll gain 200 RPM at wot on your engine for every inch of pitch you go down. If you’re running a pitch of 13 now and are getting 5600 rpm at wot you’ll get 5800 rpm if you drop the pitch to 12. Diameter also plays a role in that as you go down in diameter you’ll also increase you rpms at wot. However, you are going from an aluminum to a SS prop which changes things a bit. You see, an aluminum prop will “flatten out” when placed under load. Thus, an aluminum prop that has a pitch of 13 will flatten out to say a 12.5 under wot. SS props on the other hand don’t flatten at all under load so you may find yourself going down a little more in pitch to reach your desired rpm at wot. You want to shoot for your motor to run at its max rpm or a little lower with a light load on board.
If you do the switch I’d like to know what your results are in that I’m thinking about switching to SS myself. Good luck

[GXPWeasel]

You’ll need to know some info about your motor before you do the switch:

1. What is your engine’s max RPM? (yours is probably 6000 rpm if your rev limiter is letting you get to 5600 now)
2. What is your current prop pitch?

As a general rule you’ll gain 200 RPM at wot on your engine for every inch of pitch you go down. If you’re running a pitch of 13 now and are getting 5600 rpm at wot you’ll get 5800 rpm if you drop the pitch to 12. Diameter also plays a role in that as you go down in diameter you’ll also increase you rpms at wot. However, you are going from an aluminum to a SS prop which changes things a bit. You see, an aluminum prop will “flatten out” when placed under load. Thus, an aluminum prop that has a pitch of 13 will flatten out to say a 12.5 under wot. SS props on the other hand don’t flatten at all under load so you may find yourself going down a little more in pitch to reach your desired rpm at wot. You want to shoot for your motor to run at its max rpm or a little lower with a light load on board.
If you do the switch I’d like to know what your results are in that I’m thinking about switching to SS myself. Good luck

Good info.

[WaltF]

Another thing...
My i/o is running a mercCruiser Alpha drive.
It has that plastic 'Flo-Torq II' hub between the prop n the lower unit drive shaft.
If i hit anything that hard, the plastic hub should break first, saving my lower unit.

That feature would make me feel better if i was running an SS prop.
Although im running an AL prop cause its Cheap!

Saves more money for BEER!!