Aluminum to Steel ??? Small Outboard

[frito1]

I've got a 15/42 mod-v aluminum fish/duck boat with a 25 4 stroke Yamaha. The performance is good. Plenty quick enough off the line and a top speed of 29 mph by gps. I'm not looking to change anything other than the base material of my prop. I currently have an aluminum Yamaha prop 9 7/8 x 10 1/2. I would like to have that exact prop in steel, but no such luck. It seems my options are

Solas
10 x 10
10 3/4 x 10
10 x 11
10 1/2 x 11
10 x 10 4 blade

I realize the perfect prop would be picked by trying them all (a little pricey) and reading the tach (that I don't have), but I'm hoping someone with a similar set up or experience switching from aluminum to steel on small outboards could tell me which of the steel options would likely mirror the performance my current prop.

I realize this is probably the equivalent of a synthetic oil thread so I'll apologize in advance for asking the dumb question.

frito

BTW, I tried a friends prop just to see what would happen. He runs a 3 cylinder Yamaha 25 2 stroke. He has a 9 1/8 x 13 steel weedless. The result: A dog off the line, the same 29 mph top speed with noticably reduced rpms. But like I said above, I'm not looking for the silver bullet, just a straight cross over.

 

[gss036]

Re: Aluminum to Steel ??? Small Outboard

I think you would wasting your money on 25 HP motor as you are not going to gain anything other than bragging rights to a SS prop.

 

[frito1]

Re: Aluminum to Steel ??? Small Outboard

I think you would wasting your money on 25 HP motor as you are not going to gain anything other than bragging rights to a SS prop.

I'm not looking for anything but durability. I live in Arkansas and I duck hunt. That means running in back water, sloughs, river overflow standing in the woods, fields, and ect. An aluminum prop has a very short life expectancy in those conditions. The only reason I need a steel is so it won't bend every time it hits something.

Far as the money, the props I listed are in the $175 range. Yeah, that's double the price of aluminum, but it pays off with the first prop hit.

I used to be one of those guys that wondered why folks would lay out the $$$ for those shiny steel props. The first time my friend took me weaving through flooded timber at 0400 it all became clear.

 

[gss036]

Re: Aluminum to Steel ??? Small Outboard

The aluminum props will give when you hit something, the SS ones will not and will damage you shaft or power head. SS is not designed to go into junk and beat around brush and stumps. Cheaper to have the aluminum prop rebuilt that a power head.

 

[quackaddict1]

Re: Aluminum to Steel ??? Small Outboard

And when that aluminum prop goes to heck 20 miles from home you had better have a spare or a friend close.

Whenever this is brought up the give of the aluminum is always brought up, I though this is what rubber hubs were for? A stainless prop will be far more durable, especially since this guy is more likley to hit a stump vs a bunch of rocks.

From what I have read, you need to decrease your pitch when converting to stainless, something like 2 inches because the stainless is much more efficient. IF I were you, I would invest in a tiny tach (40$) and mount it right on the front of the motor before you buy a new prop, see where your motor is turning then buy the appropriate prop. I know you said the performance isnt a concern but longevity will be an issue if you are lugging or way over.