Max Prop v1 - locking collar

[BigAl.NZ]

Hello,

We have a Max Prop v1 on our Hood 38. The engine is a Perkins 4108.

While out of the water we noticed that the locking collar turns freely, and as the prop turns the pitch changes. I am suspect something is not right here.

https://youtu.be/Ibjna0zrWUo

The agent said that there should be a grub screw, which we could not see.


Two questions:

Anyone else familiar with the location of the grub screw?
What should the pitch be?

Thanks

AL

[fstbttms]

A Max Prop v1? That's a model of which I have never heard. Do you mean the Max Prop VP?

[BigAl.NZ]

The agent called it a Mk1 - I think there has been a few revisions to the design, but this is a early one.

[fstbttms]

Well, regardless of the model, the video appears to show the prop operating normally. It is supposed to change pitch in forward as opposed to reverse. This is why the prop is called a "feathering prop."

[nwn]

I am also the lucky owner of a Maxprop.
Is yours the one where you can set the pitch from outside by changing a ring?
If it is there should be a blocking screw that prevents moving move this ring forward and thus change the pitch.
However, the short video showed nothing abnormal. The propeller should actually change the position of blades when you reverse it. That is how it functions.
You can check the pitch by moving it to the forward position and then measure the angle to the propeller body. If it fits with the optimal for your boat, northing to worry about. The optimal pitch can be found in tables on the maxpro website

[Talulah]

As said above. Video shows prop working correctly.
Some Max props have an additional collar fitted to the shaft to take up the space between the back of the prop and the rope cutter. This sometimes occurs where a prop change has changed the length of shaft occupied by the prop.

[BigAl.NZ]

Sorry, take a look at this video - it shows my (brothers) hand moving the locking collar to change the pitch. Is that supposed to happen?

https://www.youtube.com/watch?v=oKAXyzN7x_4

[sailing_gal]

I believe that what was meant is that you have the Max Prop Classic. I had that prop on a prior boat. Yours appears to be working just fine from the video. The classic requires that you haul the boat to have the pitch adjusted. You should only let someone who has experience with that prop work on it, and I suspect your current mechanic does not. To set the pitch of the Max Prop Classic, it must be disassembled, very carefully, making note of the settings as you take the pieces off.

Max Prop's website has the owner's manual for the prop and in there, it recommends settings depending on the size of the prop and the boat. However, this is only a guideline. I have found that I have fine-tuned the pitch for optimal performance. I currently have the more modern generation of the Max Prop which, as someone mentioned above, can be pitched while in the water, so I have played with it quite a bit. Extra weight on the boat, getting maximum fuel efficiency and prop efficiency can be played with more easily when you can adjust the prop without a haulout. However, when you have to haul the boat just to adjust the pitch, it may be better to stick with the max prop recommendations in their owner's manual.

An easy test, without hauling or disassembling would be to put the boat in the water and open throttle. Are you getting most of the RPMs you would expect based on your engine's owner's manual? If significantly off, that would be your first clue that the prop is pitched wrong.

[BigAl.NZ]

Originally Posted by sailing_gal

I believe that what was meant is that you have the Max Prop Classic. I had that prop on a prior boat. Yours appears to be working just fine from the video.

Thanks for the reply.

Did you see the second video where the locking collar can be rotated?

[stormalong]

I have the same prop. PYI calls it the classic. It is the original design. From the video it appears to be working correctly. If you do not have the instruction book I suggest that you call PYI and get one. They may have it downloadable but for that I always prefer a hardcopy.

To set the pitch it has to be disassembled. The three blade version is very tricky to do without a second person helping. I know some divers claim to be able to do that underwater but to me that is crazy. The old Maxprops like yours were hand made and the internal parts are uniquely fitted to your prop. Losing a part would be a problem because the whole prop would have to be sent back to PYI to get a new part fitted.

The other comments were about the VP version of the Maxprop which can easily be re-pitched with an outside ring.

Once you have the pitch set for your engine you do not need to play with it ever again. If you do not know what your pitch setting is talk to PYI on how to determine the pitch before you take it apart. There are lettered and numbered positions on the internal parts that set the pitch. When taking it apart you will loose the setting if not very careful. Write down and save the settings.

My 1985 version needed to be taken apart to grease the prop. I saw that newer ones had holes drilled for a couple of zerk fittings so that it could be greased without disassembly. I made that change to mine which saves a huge amount of labor. The holes are filled with 6MM set screws in normal use.

PYI is very helpful with advise. Give them a call if you have questions.

PS. I see that others made the same comments while I was typing. I need to type faster.

[nwn]

OK, that looks as there is a problem. First look for a hole for a screw in the body where the ring is. There should be a screw in it locking the ring. Refitting may solve the problem.
But that did not solve a similar problem I had. We took it apart and had a lot of trouble to fit the interior of it. My experience is that you need a real expert to assemble it correctly. And I mean an expert because my experience tell me that doing it wrongly destroys the performance. When a maxPro works right it is really great.

[sailing_gal]

Just looked at the second video. That looks like it is possible that the gears in your prop need to be reground/serviced. There should not be a wobble. I had to send my prior prop into PY1 to have the gears in the prop reground. It was very expensive- over $1000 a few years ago plus shipping to the state of Washington. If that is the case, you might want to just look at the newer generation props.

Again, I strongly recommend that you have a mechanic who is familiar with the props take a look at it to determine if it needs to be serviced. It should not be difficult to find someone familiar with the prop, they are very common. Call a few marine mechanics.

[briblack]

I'm pretty sure I had the same prop, a while back. The grub screw does lock the back ring, it screws in from behind. Half of the tapped hole is in the rotating ring, half is in the hub it screws onto. Hard to see, particularly under water. I had to use a strap wrench to line it up. I think it locks the adjusting collar, that can be adjusted underwater. Sound like what you have? I could send you a couple photos that help explain, if it seems we're on the right track

[Hankasail]

Have you contacted PYI directly with your questions? If you haven't, I strongly recommend that you do. I have found the people there to be the most knowledgeable and helpful folks in the business.

[BigAl.NZ]

Yip emailed PYI today - very helpful. Haven't quite got the solution yet but getting there.