Kiwi prop causing stall into Reverse

[Hallwoves]

Hi, not sure if anyone can help, but here goes. Our Bavaria 36 is stalling going into reverse. We have had the motor serviced and it is not the motor. The mechanic suggested it could be the feathering prop (Kiwi).
To check this I either need to get in the water, which in the marina ATM isn't possible as it's zero vis, or take the boat out to Old woman where I can dive and see something or take the boat out of the water totally.
However without a reliable reverse the last two options are tricky, particularly for a novice. So my questions, 1)anyone got experience with this issues, any suggestions?

[barnakiel]

Yes. A folding / feathering prop with problems can stall an engine. Any brand.


A diver can remove the prop and you can have it tested in a repair shop.



b.

[skipperpete]

What engine do you have and what’s the idle speed?
I’m in East coast D’Albora and the vis is terrible, 6” on a good day, worse is that one of the big motor cruisers pumped out a holding tank on thursday.

[Hallwoves]

Originally Posted by skipperpete

What engine do you have and what’s the idle speed?
I’m in East coast D’Albora and the vis is terrible, 6” on a good day, worse is that one of the big motor cruisers pumped out a holding tank on thursday.

It's a Volvo Penta D130. Idles at 10000. Probably a 2004 like the boat

[Hallwoves]

Originally Posted by barnakiel

Yes. A folding / feathering prop with problems can stall an engine. Any brand.


A diver can remove the prop and you can have it tested in a repair shop.



b.

Thanks I dived under this morning and the prop seems fine.
However I can dive with gear and take it off if necessary.

[Tin Tin]

You might have line caught in the shaft that binds in reverse.

[skipperpete]

Originally Posted by Hallwoves

Thanks I dived under this morning and the prop seems fine.
However I can dive with gear and take it off if necessary.

Yeah , be careful with that, the Kiwiprop key is a thin one, most shaft keys are square cross section … not the kiwi prop one…. and if you drop it as the prop slides off the shaft it sort of ruins the day.
1000 rpm low idle is a bit too fast. Does it stall just putting er in ahead or only going from ahead to astern? Try dropping the idle back a bit and doing a very slow change into astern.

[Hallwoves]

Thanks Tin Tin. Appreciate the input.

[Jim Cate]

Have you tried manually rotating the propshaft in the reverse direction with the tranny in neutral? That should show if there is a line jamming the shaft in one direction.

Also, are there any odd noises (screeches,clunks, etc) when it stalls?

When you checked it under water did you rotate it enough (in both directions) to cause the blades to feather? If ssso, did they end up in approximately the same pitch?

The above tests might help us understand the situation better.

Jim

[Hallwoves]

Hi Jim

Thanks for those tips! I didn't try rotating in both directions so I will jump in and try that.

Much appreciated.

[SailingHarmonie]

"The Prop" doesn't seem very likely to me. In the worst possible case, the prop might be hung up internally so that in reverse it sticks with the blades fully parallel to the shaft, working as a paddle wheel and generating no forward or reverse thrust. While this would create a larger than normal load on the engine, I find it hard to imagine it actually stalling the engine at idle speed where prop loads are typically way below the engine power curve.

Of course sometimes my imagination fails to be creative enough. My thought is to not be too narrowly focused on this cause. If you can easily turn the shaft by hand from the inside of the boat, something else is going on.

That said, if you can't see any lines wrapped, I am having difficulty suggesting what else what could be the problem... So it's probably not something common...

I once had a line wrap on a feathering prop that allowed the blades to rotate, but only half way. In reverse the boat moved in reverse, in forward, the boat moved in reverse! Quite the exciting time in a close quarters situation. That was a big wad of line that was immedietly obvious to anybody looking at the prop.

[mikereed100]

When was the last time you lubed the prop? I have had this problem often with my Kiwi props over the years. You need to keep grease in the hubs or they have a hard time flipping over into reverse. This will overload a small engine, causing it to stall. Kiwiprops recommend you do this yearly but I find that they work better if done every 4 months or so. It is not difficult to lube the hub in the water if you know where the ports are.

[Lee Jerry]

Originally Posted by SailingHarmonie

"The Prop" doesn't seem very likely to me. In the worst possible case, the prop might be hung up internally so that in reverse it sticks with the blades fully parallel to the shaft, working as a paddle wheel and generating no forward or reverse thrust. While this would create a larger than normal load on the engine, I find it hard to imagine it actually stalling the engine at idle speed where prop loads are typically way below the engine power curve.

My thoughts were along this line as well.

Until I read the next post from mikereed100, who claims it can happen.

If lubing the prop doesn't fix the problem, I'd consider that the issue might be elsewhere, like in the transmission.

[Hallwoves]

Thanks for the response. The prop is free and runs, so it is something else. Not sure what yet. I have my mechanic coming back this week and will update the thread when I have a resolution.

[Hallwoves]

Thanks for the response. I will definitely be greasing the prop.