Maxprop Cutlass bearing Low RPMs

[Peterbreit]

Sorry I can't figure out how to attach pictures.
My prop is 15+ years old. The manual does not specify the model. Most likely a Classic. Handwritten on the manual is the Setting KE. which should be 20 degree pitch. Meanwhile I watched several You-tube movies also on the Max Prop web page... getting educated. I cannot adjust the pitch from the outside on my older prop.


Thanks for the pic MicHughV. What I see is the fiberglass tube attached to the hull. Your bearing is fully inside the tube held in place by the 2 set screws. The cutlass bearing is 100mm long.
Yes there is not much beef to hold the screws in the fiberglass. Maybe 2-3 mm at Best. Like one of you suggested I could have drilled into the cutlass bearing. I may do this to secure a good fit. I mounted a 30mm donut on the shaft between the cutlass bearing tube and the max prop. Had to shave it down a bit. But it keeps the bearing in place.
I talked to the yard and they will haul the boat and fix the prop setting. FWIW
My marina is across from Annapolis, MD I should have used a yard there...
Thank you All for helping.

[MicHughV]

... yes, you are correct. What I took to be the cutlass bearing is actually that fiberglass tube, painted with blue bottom paint, that extends out from the fiberglass fairing. The actual cutlass bearing fits inside that and only extends a few mm beyond that tube, and as you say is held in place by the set screws....phew....what was I thinking..... now I remember the surveyor telling me that. No need to dive on boat to check that. I was wondering why there was blue paint on the " cutlass bearing ".....it's hell getting old.

On my boat there was just enough space between the prop and the bearing to fit a small zinc collar...not the egg shaped one, but the dog collar style.
For this reason I always draped a zinc fish over the stern when at dock.

As others have pointed out, there is no doubt, that the blade settings on your max prop is wrong.

I think that 20" refers to the diameter of the prop and not the pitch. 20" seems very high to be the pitch. The letters, K and E are stamped on the gears inside the prop. I don't recall what exactly they do, but I seem to recall each mark, K and the E, refer to stampings on the the gears, one for each blade, which need to be lined up with another mark inside the prop housing.

I only ever did this one time and am working from memory.

There is a different way to set these depending on if you have a RH or LH prop.

I got my maxprop thru' PYI Inc, If you would call them, they would probably send, email or fax you the correct settings for your boat.

Not on the Beneteau, but my other boats, I have fitted a new cutlass bearing. The outside diameter of the bearing is not always the exact same as the inside diameter of the tube and some modification was always needed to make it fit. It should be a very snug fit. I always greased mine, in the event I needed to pull it.

Don't forget to ask them for the max prop grease. Apparently, there is a special kind of grease required inside that prop.

[MicHughV]

one last thing I should mention.
there is little room on the shaft to fit that zinc collar between the prop and bearing.
But when you put the engine in gear, the propshaft will move forward incrementally from the prop pressure and you don't want that zinc collar rubbing against your bearing.
So you have to fit that collar snug against the prop to allow a few mm of space between the zinc collar and the bearing.
If the collar catches on the bearing, it will try to rotate the bearing and can loosen it inside the fiberglass tube.
I would allow at least 5mm or so clear space at a minimum, but a bit more is better.

[Suijin]

I would call MaxProp and get their recommendation on the correct pitch setting for the prop for your boat. They can rattle them off without even looking it up.

And yes, having taken mine apart a few times, you have to pay attention and mark the pitch with a sharpie so you know how to easily put it back together.

I would have the yard do a quick haul and leave you in the slings during lunch and you can work on it and sort it out then. At that time I'd also check that the yard lubed it, used Locktite on the Allen screws, and inserted the cotter pins (required on some models). A lot of yard workers claim to have experience with MaxProps and then you find them fumbling around trying to figure out how to get it back together. Never confidence inspiring. Do it yourself.

[MicHughV]

I agree....with the correct settings in hand, this is a job I would prefer to do on my own.
A spare set of hands is useful though, as I recall having to keep several pieces aligned and in the correct place all at the same time.
I have the two blade version as I like to align the blades with the keel when sailing.
I have a mark on the shaft/engine coupler to indicate when the blades are upright. Not always easy to do 'cuz as soon as you rotate the shaft, the blades want to open, but I manage.

[SVHarmonie]

Originally Posted by MicHughV

I think that 20" refers to the diameter of the prop and not the pitch. 20" seems very high to be the pitch. The letters, K and E are stamped on the gears inside the prop. I don't recall what exactly they do, but I seem to recall each mark, K and the E, refer to stampings on the the gears, one for each blade, which need to be lined up with another mark inside the prop housing.

I only ever did this one time and am working from memory.

There is a different way to set these depending on if you have a RH or LH prop.

I got my maxprop thru' PYI Inc, If you would call them, they would probably send, email or fax you the correct settings for your boat.

Not on the Beneteau, but my other boats, I have fitted a new cutlass bearing. The outside diameter of the bearing is not always the exact same as the inside diameter of the tube and some modification was always needed to make it fit. It should be a very snug fit. I always greased mine, in the event I needed to pull it.

Don't forget to ask them for the max prop grease. Apparently, there is a special kind of grease required inside that prop.

Let's straighten some of this out... a 20 inch prop would be very much larger in diameter than the typical 46 foot sailboat would fit. So the number "20" is very likely to be something else.

We can be pretty sure that the "20" number refers to a blade angle of 20 DEGREES. We can be pretty sure about that because setting the cone gear to "K" and the spinner to "E" gives us a blade angle of... wait for it.... 20 degrees for a right-handed prop!

What pitch this is depends on the diameter of the prop. If it is a 16 inch prop, that would be a pitch of 11 inches, a more reasonable number than 20.

If you don't understand what those settings are, you need to download the Maxprop classic manual. I'd say it would then be clear, but until you take the prop apart and hold it in your hand the manual is likely to be more than a bit confusing.

Grease for a Maxprop is not special "Maxprop grease" but they do highly recommend using Lubriplate 130AA grease because of its extreme water-proofness. One 16 oz tube will be enough. I have used that for a dozen years, and it works extremely well.

The first time (OK, the first FIVE times) you assemble one of these you'll be sure it takes a ambidextrous, double-jointed, three-armed man to put it together. I'd like to say I have done it often enough that I can do it blindfolded, in the dark but it would be more accurate to say I can get it together on my first try in less than an hour...

[MicHughV]

yes, everything you say is correct....memories are flooding back now...I think Max Prop uses " degrees" instead of " pitch" as their blades are straight.
My first...and only.... attempt in attaching this prop to the shaft could be described as comical as I was bending over to pick dropped parts from the ground every few minutes.
Not in a million years would I attempt this underwater.

Kudo's to you for trying this underwater..

Nonetheless, I thank you for the refresher course, as I'm sure does the OP.

I believe the Max Prop diameter I have is 18" for a 43' boat, it is a 2 blade.....a 3 blade would likely be a little less...I would have to dig up the info sheet to be sure, just going from memory here.

Prior to ordering the Max Prop, I spoke with the dealer at PYI and they pretty much told me what I needed for my boat and how to set it up properly. never had a problem.

The cutlass bearing is another issue. It's possible that the OP's prop zinc has been rubbing up against this bearing causing it to get loose, but just a guess on my part.

[SaltyMetals]

Sorry, I have to disagree with Harmonie. I have a Jeanneau 43ds with exactly the same engine as the PO (4JH3TE 75 hp) and my prop is 20" diam. My new prop happens to be v similar to the maxprop but is a Featherstream from Darglow Engineering UK. So i would bet a beer or so that the 20 refers to the prop diam. The fixed blade prop which i took off was also 20".
Andrew

[fstbttms]

Originally Posted by SaltyMetals

So i would bet a beer or so that the 20 refers to the prop diam.

You're missing the point and you'd lose the bet. The number "20" was not written on the manual nor was it stamped on the prop hub or any other part of the prop. It comes from the Max Prop pitch setting chart. It is the pitch in degrees when you set the Max Prop pitch coordinates at K and E, letters that were written on the manual. While it is possible that the prop in question is 20" in diameter, that is not what the number 20 is referring to.

[sailah]

I did a cutless replacement 2 years ago and had to pull my MaxProp classic. I took copious photos of the gear settings before I moved anything important. Pulled the hub, replaced cutless and everything went together fine. Highly recommend the manual, PYI YouTube videos (which are excellent) and detailed photos.

I also took a video spinning the blades before I took the first screw off to be sure that I put them on right.

The official grease gun and Lubriplate 130AA also work very well after you put it back together. The first time I greased it, I removed the zerk and reinstalled the setscrew. Prop was locked stiff! I removed the set screw and spun the prop back and forth a few times and that released some of the pressure. Then installed screw and it has been flawless. Scared me for a min though

[fstbttms]

Interesting aside- while looking at the PYI website just now, I see that the Max Prop Classic went out of production last year.

[MicHughV]

I believe that PYI retains a bunch of "used" classic Max props.

I bought mine "used" from them. Though "used" it was in mint condition and came with a warranty.

If in the market for one of these, it might prove useful to ask PYI if they have any " used" models available. The $ price for a " used" one is a motivating factor to consider this option.

[Jim Cate]

I know that this is heresy to many on CF, but the above conversations lead me to wonder why so many think so highly of Max Props. There have been many competitive marques that have equal performance and lack the complexity of design of MP... and, dare I say it, lower prices and longer life in service. And simple external adjustment of pitch has been around for many years...

I expect howls of protest, but still I wonder...

Jim

[fstbttms]

Originally Posted by Jim Cate

There have been many competitive marques that have equal performance and lack the complexity of design of MP...

Name one or two...

[MicHughV]

I think it's name recognition....to many people, any feathering prop is a " MaxProp"......that ..plus marketing....
The name " maxprop" is just a synonym for a feathering prop....imo...at least around here..
When I decided to put a feathering prop on my boat....without thinking about it too much, decided on Maxprop.
I had some vague idea of other feathering props...but knew to next to nothing about them....

They are pricey though.....and that may cause some boaters to consider others...