Max Prop or Not?

[Cheechako]

Hard to go wrong with the Max Prop. I've had 5. Amazing difference in performance over a fixed blade or old school folding prop. However, the newer folding props seem to be getting some good rep. from users on this forum (Flex-O-fold?)
Max prop is well proven though.
Another take on spending the money though: Do you try to sail in light winds? or just turn on the "Iron Reacher" and motor sail? I tend to motorsail in anything under 3.5 -4 knots boat speed. I s the cost of a max prop worth it as such? hmmm... your boat will probably do hull speed in 15 knots of wind with a fixed prop anyway. I will say the reverse thrust of the Max Prop saved my bacon in heavy current docking situations more than once.
I would not spend extra money on more than 3 blades....

[Chalifour]

Based on our experience, Max prop is a definite advantage. Combine with a Yanmar 70HP we sense no need for a Bowtruster on our Jeanneau DS43. The 3-blade prop give us 90% backward trust with minimal prop path. Very, very convenient in the Mediterranean where stern docking is the norm and space in ports and marinas often limited. Get the right model and go for it.

[Terra Nova]

The Max Prop is a very worthwhile upgrade. But you'll want to calibrate your tachometer before pursuing this further.

Be extremely careful handling the individual Max Prop components, as the slightest nick or burr on the internals can defeat its normal operation. On several installations I have found it necessary to deburr and lap some of the components with valve grinding compound, to get the prop to self-feather.

[wesevans]

I have had a max prop on two sail boats. I found it to be worth the money. I loved it. Slight improvement under sail and almost full power in reverse. A great help if you run aground. I like 3 blades with the max prop.

[serannity]

You might consider another option, a folding prop. We installed a three blade "Flexofold" on our 48' ketch while in Thailand and have added more than 25,000 miles since. It has added up to 2 knots over our three blade fixed prop and even improved our hull speed. I wish we had it for the first 14 years of ocean cruising.

Take a look at "www.flexofold.com"

[cwyckham]

Autostream is another option for a feathering prop. We have one and love it.

[Moody46CC]

US Distributor or Agent for Autoprop is

AB Marine, Inc
747 Aquidneck Ave
Middletown, RI 02842
Tel:401.847.7960
Fax: 401.849.0631



I have had both a max prop (on a 38' Moody) and an autoprop (on a 46' Moody). Like IPs, Moodys are heavy boats but they have fin keels, not full keels. The only difference I can see is the autoprop accelerates a little faster. Both require greasing annually, and I do that at haul-out when changing zincs and touching up bottom paint. Both require a zinc on the end and it must be changed annually.

When sailing, I'll leave the engine in reverse gear to feather the autoprop properly. You can hear it turning when below if it is not feathered.

Otherwise, pretty much maintenance free.

[a64pilot]

Moody,
When you motorsail either, does the autoprop allow you to do so at a lower RPM?
If I understand it, they auto pitch and motorsailing should allow the prop to have a higher pitch and provide thrust at a lower engine RPM, is this true?

[Tayana42]

Very happy with my MaxProp. It came as original with the boat 1989 Tayana 42 with Yanmar 4jhe 44 hp, 28,000 lb boat. Good drive in forward or reverse. No noticeable prop walk. Did have to readjust setting after yard removed it to rebuild the shaft tube and set it up differently. Once you get yours set properly record the settings so you can get back to same settings easily.

[Moody46CC]

Originally Posted by a64pilot

Moody,
When you motorsail either, does the autoprop allow you to do so at a lower RPM?
If I understand it, they auto pitch and motorsailing should allow the prop to have a higher pitch and provide thrust at a lower engine RPM, is this true?

It is supposed to work in this manner. I think it does, but the autoprop came with the boat so I have no comparison to motor sailing with a fixed blade prop. I say I think it works, because the number of rpms necessary to hold a steady speed will vary considerably with conditions. I have the three blade H6 model.

[a64pilot]

Originally Posted by Moody46CC

I say I think it works, because the number of rpms necessary to hold a steady speed will vary considerably with conditions. I have the three blade H6 model.

From my understanding that is exactly what it is supposed to do, and ideally what I want, sort of functions like a CVT on a car. Have you had any service problems? I've read about bearing failures, don't know if that was only the open to water bearings, or the newer, greased bearings, or if it's internet hype as I've never seen an Autoprop.
So far sounds like what I'm after, and I got a price that is close to a Max Prop

[fstbttms]

The Autoprop failures were not internet hype. I have witnessed such failures multiple times. That said, the prop has apparently been redesigned to eliminate these problems. However (for whatever reason) Autoprop never really caught on in my neck of the woods and I have yet to come across one of these newer models and so cannot report any first hand knowledge of whether they are an improvement or not.

[Moody46CC]

Originally Posted by a64pilot

From my understanding that is exactly what it is supposed to do, and ideally what I want, sort of functions like a CVT on a car. Have you had any service problems? I've read about bearing failures, don't know if that was only the open to water bearings, or the newer, greased bearings, or if it's internet hype as I've never seen an Autoprop.
So far sounds like what I'm after, and I got a price that is close to a Max Prop

Maintenance is easy. The previous owner left me the grease gun and special zerk fitting. Each of the three blades has two fittings--one at its base on the hub and one at the tip of each of the blade hubs. Take out the allen screw in each of the fittings, put the zerk into one, and pump grease until it oozes out the other open fitting. Twist the blades a bit to open all the cavities as you pump grease, then put the allen screws back in. That is it. If the bearings get loose, one can buy replacement kits from the distributor. One can get the grease zerk from them as well. I suppose a diver could do this, but I always haul the boat at least once or twice annually and do it in one of the haul outs.

My boat is a 2000 model but I've only owned her two years, so I can't really address bearing failures. The autoprop was installed in 2006 and the PO never mentioned any issues--he swore by it.

A fellow called Dockhead addressed some questions earlier in this thread, and he said he's had an autoprop on his Moody for a longer time. Ask him about his experience. He was quite favorable and seems to have logged far more miles and time than I have. His boat is larger and 10 tons heavier than mine, so if displacement is a factor in wear and tear, he can address that.

And I had a positive experience w/o any maintenance issues with an maxprop on my smaller Moody--a 38 that weighed 18000 lbs and had the 4JH3 Yanmar. My current Moody has that engine as well, but it is the 75 hp turbo version, the 4JH3-TE.

Check with Dockhead.

[cwyckham]

Originally Posted by Moody46CC

Maintenance is easy. The previous owner left me the grease gun and special zerk fitting. Each of the three blades has two fittings--one at its base on the hub and one at the tip of each of the blade hubs. Take out the allen screw in each of the fittings, put the zerk into one, and pump grease until it oozes out the other open fitting. Twist the blades a bit to open all the cavities as you pump grease, then put the allen screws back in. That is it. If the bearings get loose, one can buy replacement kits from the distributor. One can get the grease zerk from them as well. I suppose a diver could do this, but I always haul the boat at least once or twice annually and do it in one of the haul outs.

My boat is a 2000 model but I've only owned her two years, so I can't really address bearing failures. The autoprop was installed in 2006 and the PO never mentioned any issues--he swore by it.

A fellow called Dockhead addressed some questions earlier in this thread, and he said he's had an autoprop on his Moody for a longer time. Ask him about his experience. He was quite favorable and seems to have logged far more miles and time than I have. His boat is larger and 10 tons heavier than mine, so if displacement is a factor in wear and tear, he can address that.

And I had a positive experience w/o any maintenance issues with an maxprop on my smaller Moody--a 38 that weighed 18000 lbs and had the 4JH3 Yanmar. My current Moody has that engine as well, but it is the 75 hp turbo version, the 4JH3-TE.

Check with Dockhead.

yikes. I only have one standard grease nipple on my autostream and I can grease it on a single breath of air in the water.

[UNCIVILIZED]

Get a Max-Prop, I Highly doubt that you'll have any regrets. I've driven yachts with most of the prop types out there, with the exception of some of the new stuff in say the last 5 years or so, & with ZERO question for me, the Max-Props are head & shoulders above everything else.

For example, a race boat which I looked after for a while (45', 9 tons), had her prop, a twin bladed Max-Prop, right behind the fin keel. A good 15' from the rudder, so there was ZERO steerage from prop thrust over the rudder. Meaning that you had to be doing 3 knots to have ANY steerage. Which can make a boat a beast to dock in close quarters. But I never had any problems or worries boat handling under those kinds of conditions, as the prop would provide so much thrust as soon as I shifted directions, transmission wise. And this was up in the Pacific NW, where a lot of the time the winds around there define the word fierce.

Before you get a Max-Prop, spend some time digging around on their website, and in addition, put together a few questions and; call them direct & ask, but also call one or two of their distributors/re-sellers with your questions as well. That way, you can get your questions answered, but perhaps more importantly, get a feel for their customer support & what kind of backup is provided, along with how well the company does in terms of educating those who carry & service their products.
Something which is probably a wise idea on any 4-digit (+) purchase.

It would also be wise to do a bit of online research into numbers of blades on a propeller vs. size, in order to see what makes the most sense for you size & dollar wise. Particularly as with more efficient propellers, like the Max-Prop, at times, the cliché "less is more" is very true. Meaning that having fewer blades (of a given design) is actually more efficient than more.
It's a thing which a lot of people are rather resistant to believing, but the math don't lie. Other than Google, Practical Sailor might be a place to start, in addition to Max-Prop themselves.

Also, just to be clear, I think that dockhead is referring to another brand of prop when he mentions no gearing. However, Max-Props DEFINITELY are geared, as can be seen here -- PYI Inc. Max-Prop PSS Shaft Seal Seaview Radar Mounts R&D -- in addition to several other places on their website.

Plus, spend the coin, & get your current propeller correctly pitched. It's a quick & inexpensive job for any decent shop. If naught else, keep it around as a spare.

One final thought (despite me still batting for the Max-Prop), some folks will keep both an old school, folding prop on hand, as well as a fixed bladed one. And when they're in conditions where they'll be motoring, or motor sailing a lot, they'll use the fixed prop. But for times when they're primarily sailing, they'll switch to the folder.
Neither of these has the efficiency, or low drag of a Max-Prop, but price wise, the 2 together, are cheaper than a Max-Prop.