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#11 Crazyhorse

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Posted 10 November 2018 - 06:41 AM

Down this road last year when cleaning our prop for prop speed got the numbers off it and looked it up on briski's website. Wrong size prop. Took it to Arthur at the prop shop with details of engine and gear box ratio ( a nightmare trying to read that off the back) and got it repitched. What a difference! The engine doesn't blow black smoke and when we had the head off was not coked up so all running sweet. One thing I do though is adjust throttle settings every now and then when underway. Engines don't like spending hours on one setting, it "polishes" the cylinders I've been told.
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#12 lateral

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Posted 10 November 2018 - 07:35 AM

I've lost 1/2 a knot at 2500 with the new kiwi prop.

But, its way quieter, smoother, cleaner exhaust. No smoke.

Now I can run at 3000rpm no problem.

Before a rhythmic vibration, made it uncomfortable.


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#13 Steve Pope

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Posted 10 November 2018 - 08:06 AM

Because the kiwi prop is much lighter than any fixed bronze prop, as all the weight involved is in the boss and minimum weight at the blades.

I have had to re-pitch mine well past the optimum recommended in the manual to get close to the speed I had with the fixed original.

A downside I do have is that it has a habit of jamming in ahead mode and the spring not being strong enough  to allow it to either free wheel or feather. I have to dive and hold a blade while rotating the shaft with a 1/2 inch drive tommy bar.


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#14 lateral

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Posted 10 November 2018 - 08:47 AM

The spring should bring it back to zero pitch as soon as shaft stops spinning, right?

Wonder why it is jamming. Did it do it from new?

I have to put mine in gear to get it to feather other wise it spins so eventually I may end up with the same problem.

More grease?


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#15 Steve Pope

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Posted 10 November 2018 - 01:30 PM

Definitely not a lack of grease, Why it jams, i've no idea. As soon as I do the tommy bar thing it is back to normal with the spring working. I will remove it and strip it at some stage. Frustrating.


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#16 Island Time

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Posted 10 November 2018 - 02:18 PM

it can jam if over pitched. If you have to overpitch, then the prop is too small. Talk with Kiwiprop, they are good at this!


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