Kiwi prop - Composite Variable pitch

[Jon Hacking]

Originally Posted by mikereed100

... We too cannot bring our engines to full rpms in reverse due to the over-pitching of the props in reverse, but find that we still get plenty of thrust. We set our anchor using a 2 step process. Step one is to back down gradually, allowing the anchor to dig in. We then put the engines in neutral which allows the boat to spring forward. Step 2 is to reverse again, gaining some speed, 2-3 knots usually. When we fetch up on the rode the jerking action puts a lot more force on the anchor than simply backing down and we know we are well set.

Good technique, Mike. Snatching on the anchor puts more strain on the gear, & it's less repeatable (sorry, I'm an engineer), but it would likely set it more deeply than just pulling on it at low RPMs.

But the mere fact that you have to do this shows that you're not getting much power into the water in reverse, that you're not, in fact, getting "plenty of thrust." Some thrust? Sure. More thrust than at comparable RPMs in forward? Yes, because of the increased pitch in reverse.

But if you can't get up to the RPMs where your engines produce their real power (& the curve is always climbing with RPMs, so max is at the top of their rev-range) then you're not going to be able to get the power of your engines into the water. And this can be crucial in a crash-stop situation, like suddenly seeing a net or a reef, right ahead of you.

[GILow]

Originally Posted by Jon Hacking

They're for sail-drives. They all have the same splined (not tapered) shaft, & the same rotation.



Unfortunately, Ocelot's on the hard in Kudat, northern Borneo, & we're in Chile. It's going to be a few more months before we can return to her...

Darn. I’m looking for a 1.25” shaft version.

[Kiwi Dave]

Hi all
I can only speak from personal experience 45' cat with 2 Volvo D1-30 engines, sail drives and Kiwi Props. We have has CATMANTOO for 10 years, props were on her prior to that.
I managed to wrap my Code 0 sheet around one prop while maneuvering to anchor. Engine stalled, prop undamaged.

https://www.youtube.com/watch?v=bx4i..._jEpt&index=10

Previous owner did break blades by hitting a reef - just replaced the blades with a spare set (smaller blades that were used with the previous 20HP engines), I still have these on board.

I managed to pick up another floating piece of rope around one - no damage.

Maintenance is a breeze (NZ web site has all the info). Re-pitching is easy. Prop Guard sticks to the blades without the primer.

[bgallinger]

Originally Posted by Wckoek

https://www.kiwiprops.co.nz/cms/
Looks interesting and not expensive either.
Has anyone tried their propeller?
Any drawbacks to composite blades vs bronze?

I've had a Kiwi prop on my boat for 10 years and encountered only one problem after spending time on the ICW. This prop does not like dirt, grit and sand getting in and the prop would not go into reverse. This prop also needs grease and lots of it applied frequently. I did send it in for repairs to the Kiwi service center near Toronto and shipping costs were $55 CDN from Toronto to London, Ont. That's highway robbery, but it's Canada.

[pcmm]

I've had no issues with my kiwiprop so far. Yes it goes to a higher pitch in reverse, but most transmissions seem to have lower gearing in reverse (which compensates)...Other than my KM4A which has identical gearing in both directions (its a bi-directional transmission). even with that I can get to 2500 rm in reverse. The Poster who can't get to 1400 in reverse likely has some other issues or has overpropped themselves. Kiwiprop guys are very good at sizing ( if a bit conservative) I've pitched up my forward setting slightly from what it came set to from the factory. Maintenance is very easy, and occasional tear down to give it a good clean also easy (it helps that they have online videos explaining the process).