Need some prop advice!!!

[Ribfisher]

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HI,
At this moment I use a alu .prop 17" on a Ribtec 585 with a Honda 90 HP.
Cruising speed 24 Kn at 4500 rpm -full trottle 32 kn at 5400 rpm.(Heavy load)
However I want to use the full powerband of the engine and I want to go
to 6000rpm.
Could that be possible with a 17" Stainless Steel prop?
Which brand,type should I order?

[simmons0]

Changing from an Ali prop to a stainless of the same size would reduce the max revs you will acheive.In order to get that extra 600rpm you would probably need a 15" stainless.
Worth trying before you buy though

[Mike C]

Hi Ribfisher,

No just changing to steel, same pitch, will make little difference to the top end revs, (Except as simmonso says - if anything drop it)

You need to drop to a smaller pitch prop... be it steel or ali. You need an extra 600 revs so in theory you need to drop 3” to a 14". That isn't standard so the choice will probably be a 13" or 15".

That’s the theory, but as has been discussed on another thread... some trial and testing may be necessary!

17” does seem a bit high on a 5.85 with a 90hp…. I had 15” on my 60hp on my 5.85… but that was a twin set-up.

Mike C

[Ribfisher]

Thanks for reply,ribbers
Just found somewone who's imports TP. (turning point) props from the US.
He's got the whole range to testing with.