Stainless vs alu prop

paradave

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We have a alu prop on our Yamaha 130 outboard and in all honesty, the performance is great. Is there much benefit investing in a SS prop? Any significant performance or economy gains for example?
Be interested to hear in anyone’s experience. If it’s relevant, currently WOT is 32knts and cruise 22-25. Thanks.
 
Absolutely no need to replace (yet) but seems a reasonably priced upgrade - I was curious how much difference it made.

Extra speed is always nice but for our little boat, it's easily fast enough really!
 
We have a alu prop on our Yamaha 130 outboard and in all honesty, the performance is great. Is there much benefit investing in a SS prop? Any significant performance or economy gains for example?
Be interested to hear in anyone’s experience. If it’s relevant, currently WOT is 32knts and cruise 22-25. Thanks.

What's the WOT range for your engine? And what was the max rpm at 32 knots?

From that you can calculate prop slip which give a clue to efficiency.

I'm changing to a stainless prop on my new Honda 100 once I've run the engine in.

Once I know my WOT them I'll decide of the correct pitch...
 
I've had stainless on a couple of small boats and think it's worth an extra pitch of prop but a poor stainless design can be outperformed by a good alu one such as a Turning Point Hustler for which you won't find a bad review.

At the same time also worth also considering a switch to a four blade to reduce slip especially at cruising rpms and improve economy. I had a good experience with a Solas stainless four blade and the material compensated for what I would have lost on top end compared to the old three blade alu. The extra grip was easily demonstrated by travelling in someone's aerated wake which didn't seem to phase it like before.
 
What's the WOT range for your engine? And what was the max rpm at 32 knots?

From that you can calculate prop slip which give a clue to efficiency.

I'm changing to a stainless prop on my new Honda 100 once I've run the engine in.

Once I know my WOT them I'll decide of the correct pitch...
Max revs for engine 5300-6300 according to manual. I can’t recall what it was at whilst at 32knts, possibly 5800.
 
Worth repeating that it's worthwhile optimizing the engine height before any change of prop. This alone can be worth two pitches and dealers universally seem to set outboards low to be on the safe side. They don't want to be doing the job twice if they erred the other way.

It's easily done without a hoist if the boat is on a trailer.

@paradave what engine and pitch do you have on now?
 
I’ve got a Yamaha f130 - not too sure on pitch, I’m hopefully on her on Friday so shall have a look.
 
Hi. Tough one in this case. Just because the prop you likely have on her now will most likely be the excellent (for an ally) k series prop. They are brilliant for an ally prop. To better it, you’d really need to go for a really good stainless prop from mercury. I am almost certain that any cheap stainless prop from the likes of solas or similar, may be a disappointment. Stick to a 3 blade too, I’d say. If it’s performance you’re after.
All depends on the boat and a few other variables too of course.
 
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