Stainless prop

Archie1977 · 30 August 2022, 18:20

Hi has anyone used a stainless steel prop on a Yamaha 25 hp 4 stroke high thrust
Any info would be appreciated
Thanks Archie

Matt · 30 August 2022, 18:25

I have an opinion, but I’ll hold fire pending someone who’s actually tried it coming along.

Roflhat · 30 August 2022, 19:15

What boat setup is it on? Unless it's a performance boat probably not worth the expense

Matt · 30 August 2022, 22:16

Stainless props have 2 characteristics. Thinner blades and more stiffness.

On a 25 hp high thrust setup, I really don’t think you’d notice the difference at all from this. If you were running a race boat, surfacing the prop and looking for the last 0.1 mph, for sure it could help, but I doubt that’s where you are. So I reckon your money would be better spent elsewhere, unless you just want the bling

paintman · 31 August 2022, 08:58

Fitted a stainless to my Mercury 135. Much heavier than the ally props.
A downside is the amount of noise you get putting it into gear - far more than the lighter ally ones - and I do wonder what that does for the gears.

Matt · 31 August 2022, 09:12

I remember a conversation with the Folly Water Taxi guy a few years ago - they put, as you'd expect, thousands and thousands of hours on their motors, in and out of gear all the time. I seem to remember he reckoned they'd easily put a couple of thousand hours on a motor (don't quote me on that bit though)

The weakest link on the motors was the gearboxes. It was their experience that the mistake most people make on an outboard gearbox is to "tickle" it into gear. They found this wore the clutch dogs out more quickly, as it "clips" the clutch dogs before engaging fully. Much better to clunk it positively into gear so the dogs fully engage instantly. Counterintuitive since we're all used to automotive clutches, but if you think about it, makes perfect sense.

Wherease a bravo drive, or conventional transmission (e.g. shafts and not a crash box) that uses clutches - does work better with a bit more finesse.

Roflhat · 31 August 2022, 17:03

I try and switch the engine off, shift into fwd or reverse then pull start again. Over the top I know but the 70ces gearboxes are like hens teeth. I do it 100% of the time with the solid hub racing cleavers, even with the normal 15p rubber hub prop I like to do it fairly often

Matt · 31 August 2022, 17:37

For your "loon" setup, that's fair. I wouldn't recommend it for "joe average" though.

What gear oil do you run? Have you tried ATF for a bit extra top end yet?

Archie1977 · 31 August 2022, 17:39

Hi thanks for all your reply's, alloy it is then, boat is a 4 m ribeye centre console
Next question what pitch are people running ?? Thanks Archie

jeffstevens763@g · 31 August 2022, 19:07

I found on my 90 Suzuki stainless prop didn’t give any difference in performance but then no day is the same just my two pence

Roflhat · 31 August 2022, 20:45

Quote:

Originally Posted by Matt

For your "loon" setup, that's fair. I wouldn't recommend it for "joe average" though.

What gear oil do you run? Have you tried ATF for a bit extra top end yet?

Yeh definitely a bit of a faff. I've tried a few different gearbox oils, I now run ATF all the time. No difference in my results in testing but all the F4 guys swore by it in the 70ces