Should prop spin in Reverse?

[Tally Ho]

Hi all,

I installed a new 3-blade Maxprop feathering prop over the winter…hoping to get a little more speed in light air, hope to reduce some vibration vs my 2-blade fixed prop, and I like the reverse thrust of the new prop.

After a false start where I somehow messed the prop rotation (still not sure exactly what I did, but it was self-inflicted), the prop works great…fantastic power in REV, less vibration while motoring, and similar performance in FWD to my fixed prop (maybe better). And I can get 3600 RPMs without blowing unburned fuel out the exhaust…so that is all great.

I am having problems getting the prop to feather though…..
I have tried putting the transmission in REV after killing the engine in neutral… but the shaft is still turning.
I tried shutting the engine off in FWD, them moving transmission to neutral…but shaft still spinning.i can get it to feather by stopping the shaft by hand in the engine bilge. And once I stop it, the prop feathers and no more shaft rotation.

So 2 questions:
1) for those with a MaxProp, what steps do you take to feather the prop?

2) For those familiar with a Kanzaki transmission, should the shaft turn in FWD and REV with the engine off? I thought either one of these would lock the shaft so it would turn….do I have a transmission rebuild in my future! Mine is a KM2P.

Water temp in Lake Michigan was about 44 F today … doubt that has anything to do with the feathering, but the grease has to be pretty cold (and stiff?) in the prop.

Appreciate any comments or suggestions.

Greg

 

[kappykaplan]

1) for those with a MaxProp, what steps do you take to feather the prop?

I put the transmission in neutral, shut down the engine, then shift into reverse to feather the prop, then shift to neutral. What is your boat speed when attempting to feather? Believe you need at least three knots for the MaxProp to feather.

 

[Don S/V ILLusion]

Believe you need at least three knots for the MaxProp to feather.

my experience too plus current can also affect when/if it feathers

 

[quadrille38]

The instructions from Max Prop say to shut engine off while still in forward at idle speed. The blades will feather. After about a minute shift into neutral and leave it there.
Has worked flawlessly for me for years.


Here is the text from the Maxprop web site

Modern transmissions are either mechanical or hydraulic. There are also mechanical and electronic controls for these transmissions. The procedure to feather the Max-Prop depends on the type of transmission and control being used.
NOTE: Water flow over the blades, combined with drag on the propeller shaft enable the Max-Prop to feather automatically. Follow these procedures to feather your Max-Prop:
Mechanical Transmission with mechanical controls:

• Power at 2 to 3 knots in forward.
• Kill the engine with the transmission still engaged in forward. The drag of the mechanical transmission should result in sufficient drag on the shaft for the Max-Prop to feather.
• If your propeller has been greased properly, it will feather in a fraction of a second.
• If the propeller has not yet feathered (shaft still rotates under sail), more drag can be added to the shaft of a mechanical transmission by engaging the transmission in reverse, with the engine OFF (WARNING: engage reverse only after the engine has stopped completely).
• After the Max-Prop has feathered, the transmission can be placed back into neutral.

 

[FastOlson]

I used a very similar feathering prop from Martec. Two blades. It needed 4 or 5 knots of speed when putting trans. into neutral and then it would feather. However, we get very cold water in our river in the spring and this would slightly stiffen the grease and slow down the feathering. This could be a tad frustrating.

It helps to have a grease that maintains its viscosity at lower temps, like the one that PYI sells. I bought some from them when the local auto parts store could not seem to get any.

Max-Prop Grease

Keep your Max-Prop running like new with Lubriplate LU 130-AA calcium based grease.

store.pyiinc.com

It's not really a "special" grease, because most any marine-rated grease might do fine, but you need a product that will flow at lower temps.

 

[Tally Ho]

I put the transmission in neutral, shut down the engine, then shift into reverse to feather the prop, then shift to neutral. What is your boat speed when attempting to feather? Believe you need at least three knots for the MaxProp to feather.

Certainly above 3 knots when I tried to feather. 4-5 knots boat speed.

 

[Tally Ho]

my experience too plus current can also affect when/if it feathers

Lake Michigan….no current.

 

[Tally Ho]

The instructions from Max Prop say to shut engine off while still in forward at idle speed. The blades will feather. After about a minute shift into neutral and leave it there.
Has worked flawlessly for me for years.


Here is the text from the Maxprop web site

Modern transmissions are either mechanical or hydraulic. There are also mechanical and electronic controls for these transmissions. The procedure to feather the Max-Prop depends on the type of transmission and control being used.
NOTE: Water flow over the blades, combined with drag on the propeller shaft enable the Max-Prop to feather automatically. Follow these procedures to feather your Max-Prop:
Mechanical Transmission with mechanical controls:

• Power at 2 to 3 knots in forward.
• Kill the engine with the transmission still engaged in forward. The drag of the mechanical transmission should result in sufficient drag on the shaft for the Max-Prop to feather.
• If your propeller has been greased properly, it will feather in a fraction of a second.
• If the propeller has not yet feathered (shaft still rotates under sail), more drag can be added to the shaft of a mechanical transmission by engaging the transmission in reverse, with the engine OFF (WARNING: engage reverse only after the engine has stopped completely).
• After the Max-Prop has feathered, the transmission can be placed back into neutral.

I will try again tomorrow. What if boat speed is more than 2-3 knots?

Should a mechanical transmission allow the shaft to turn in FWD? when the engine is shut down?

Thanks all for the comments.


Greg

 

[Tally Ho]

I used a very similar feathering prop from Martec. Two blades. It needed 4 or 5 knots of speed when putting trans. into neutral and then it would feather. However, we get very cold water in our river in the spring and this would slightly stiffen the grease and slow down the feathering. This could be a tad frustrating.

It helps to have a grease that maintains its viscosity at lower temps, like the one that PYI sells. I bought some from them when the local auto parts store could not seem to get any.

Max-Prop Grease

Keep your Max-Prop running like new with Lubriplate LU 130-AA calcium based grease.

store.pyiinc.com

It's not really a "special" grease, because most any marine-rated grease might do fine, but you need a product that will flow at lower temps.

That is the grease that came with my prop.

Greg

 

[Calif. Ted]

Should a mechanical transmission allow the shaft to turn in FWD? when the engine is shut down?

It has always been my experience that the shaft is not free to turn while in either gear when engine is off.

 

[arf145]

I usually shut the engine off in forward, then shift to reverse briefly and then leave it in neutral.

 

[Tally Ho]

I usually shut the engine off in forward, then shift to reverse briefly and then leave it in neutral.

Thanks Tom.
I will give that a try too.

Greg

 

[Tally Ho]

It has always been my experience that the shaft is not free to turn while in either gear when engine is off.

I think I better understand how the transmission works now that iam at the boat inspecting things…

In FWD, the shaft will rotate freely in one direction…in REV, it will rotate freely the other way. In Neutral, it rotates freely in both directions.

I guess this makes sense (good news my transmission isn’t messed up). So, now I just have to get the sequence down properly to get the prop to feather (without going below and stopping the shaft by hand).

I will try the techniques / sequences suggested…

Thanks for the input.

Greg

 

[Tally Ho]

Many thanks to you guys for your comments. I can report that I sailed this morning in fairly light winds ( 8-12 knots), and was able to feather the Max Prop very easily using a combination of suggestions above.

Basically, I shut engine off in neutral as I usually do. Then shifted to forward briefly, the to reverse, and then to neutral. Prop was feathered and shaft was still the rest of my 10 NM sail.



Thanks for all of the good info and advice.

Greg

 

[kappykaplan]

Thanks for all of the good info and advice.

Quite welcome.