Stainless Prop Advice Wanted

[Stormchild]

I have a 2005 Suzuki DF115TUL which has its original 15' 23' Ali prop. I'm thinking about changing this for a stainless prop of similar size and spec. I know that when it comes to props it almost a science in its own right and choosing the right one can be a tricky business.
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I'm getting about 37 - 39 knots top speed currently, the boat handles fine and the main issues are strength of the stainless steel, giving better acceleration, handling & fuel economy.
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But are are there any real pit falls I need to be watching out for. I've seen a 14'' diameter 22'' pitch unit for sale second hand, which I think will do the job.

But any help and advice is greatly appreciated !

[Downhilldai]

You'll lose around 5% top speed if you drop an inch pitch, but acceleration will improve, which may be a bonus if you're pulling waterskiers. Performance will depend on whether the current prop is 'geared' correctly to your boat. When you're at full throttle with normal loading, what RPM are you hitting?

[Stormchild]

I've got full instrumentation with rev counter and all the gizmo's inc a speedo in MPH and I've also got a Garmin 188C which gives me a pretty accurate speed over ground in Knots.

I would say the current prop is about perfectly matched for the boat as the manufacturers information states max operating speed is 5000 - 6000 RPM and I'm getting a knats over 6000 RPM.

should I be going for the same diameter & pitch but in stainless ? - This seems the logical answer ?

[Alice]

Originally Posted by Downhilldai

You'll lose around 5% top speed if you drop an inch pitch, but acceleration will improve,

Would that be on the surface or submerged?

[Hightower]

If you do a search on the forum about Stainless props you'll find out all the info you require.

Dis-advantages are the price, if you hit something with your prop then gearbox damage is more likely. That's about it.

With me I tried quite a few different props and in the end chose an Alloy one (have two really, one for heavy loads/difficult weather and one for light loads and good weather). Choosing any prop is a bit of a black art as the computations of different Hull types V Engines is a difficult one to accuratly calculate on paper.

If you are interested in a prop why not ask if you can trial it before you buy.

[Downhilldai]

If you're making 6000+ RPM with your normal loading and regularly run at that sort of speed, I would suggest keeping to the same spec, or even adding an inch of pitch, which will probably get you the same top end, but at a saving in 300ish RPM. The prop you've seen for sale will in all likelihood result in over-revving your motor at full chat. As Hightower says, the best solution is to 'try before you buy'. Some dealers keep a range of props they use when rigging new outboards, to get the best matched prop to the boat. If you have a dealer in your locality who can assist, it's probably worth an hour or so of fitter's labour to get it right. If you take this route, the dealer may waive the labour charge if he secures a sale of a shiny new lump of stainless...
Best of luck. Let us know where you go on this and what results you get.

Originally Posted by Alice

Would that be on the surface or submerged?

Planning on venturing into foreign waters again this weekend. Better pump the tubes up for some added buoyancy

[Stormchild]

Thanks, yeah will do. We cant always run at that speed, - my younger brother is a jet skier and I'm in the process of re educating him into really sexy things....... so running with the jet ski's is something we tend to do a fair bit of. They ride a couple of Kawi 900's and my rib is about 2 - 3 mph / a couple of knots or so slower than it when the sea's are calm enough to run flat out, that said I can still reach that speed 3 up. In the chop he's only good for about 15 minutes flat out at most before he just falls over and we end up draggin him out. His re education is happening slowly.......i'll let you know how I get on and how a stainless prop makes a difference to the boats performance.
The worrying bit is the cost of a new one is mildly excessive......the missus says if she catches me buyin one she's gonna zip me todger up in me flies......and I've seen theres something about mary.......

still if you see a nice rib tearing by @ 40 knots and the drivers got a funny walk, you'll know I got my stainless prop !

[Downhilldai]

Originally Posted by Stormchild

The worrying bit is the cost of a new one is mildly excessive......the missus says if she catches me buyin one she's gonna zip me todger up in me flies......an

Aluminium's nice

[jyasaki]

Originally Posted by Stormchild

the missus says if she catches me buyin one she's gonna zip me todger up in me flies......and I've seen theres something about mary.......

I know a guy who did this in Belize. Zipped himself up in his dive skin. About an inch worth of, well, you get the idea. Took a pair of EMT shears, a pair of pliers, and a set of channel locks to extricate his, er, anatomy.

Go aluminum. Your anatomy will thank you.

jky

[tinker]

Hi,
just ordered this :-

>10 3/8 RH 14 APOLLO
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>3 Blade Stainless Steel
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>With Mercury Hub Assembly
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>Part# 993407-114
>
>$165.00
>
>
>
>Shipping to UK
>
>USPS AIR
>
>$46.40

deltaprop.com

plus 2.7% import tax and 17.5% vat and 2.5% cc fees but still works out at around £145 very reasonable, paid via cc over the phone, not arrived yet but got the ups tracking number and seems ok, will see
mark

[DGR]

I struggle beating the jetskiers on a flat day - but once there is a bit of chop, NO PROBLEM!! (and all my teeth stay in my head as well, which is a definate bonus.)

Does anyone know whether a 1" increase in pitch for an ali prop has the same effect as a 1" pitch change on a stainless prop?

Mine (SS) over revs, but only by about 100-150 rpm, so I'm not going to worry about it (too much). But would I lose the 'rough' guesstimate of 300 rpm if I went up an inch?!?

Also, are there any tablets I can get for my prop, as I get lots of offers via e-mail for increasing size by 'x'-inches.........

D...

[ashbypower]

A 1" increase ion pitch equates to around 200 RPM decrease and Vica Versa. You could always get your prop repitched for a resonable sum, I believe Prop Revs, Poole charge around 40 squids.

Brian