# MaxProp or Autoprop?



## LJD (Oct 2, 2008)

We are going to buy a new prop for our 40' Island Packet and wonder if anyone can share their opinions on these two props. We have a Prowell feathering prop that is 15 years old and we think it's time to replace it. It seems that the Autoprop will be easier to install and has the advantage of having no pitch adjustments to make. However, it's priced a lot higher than the MaxProp which seems to be popular as well. Your opinons will be appreciated!
LJD


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## Capnblu (Mar 17, 2006)

I just saw a KIWI prop at the Vancouver boat show. I looked the thing over real good, and it is a good looking unit as far as the machining goes. It was made totally out of stainless parts. To me I like the idea of SIMILAR metals in contact with the brine. It was adjustable, foreward and reverse like the MAX but quite a bit simpler design. I am sure the drag of the KIWI will be higher, due to the design of the foils, and the 3 stops for the blades. The KIWI could be had today in Canadian currency for $1200-1400 for a 18" feathering prop out of solid stainless, with some type of polycarbonate blade? Sorry if the material is wrong (some one is liable to know what it is.) The KIWI is priced good in my point of view, It would cost me only slightly less to make one, and be a PITA with the machines I currently have. I easily could have made a MAX for what they retail. As for the AUTO PROP it was a sleeker design, almost like a stainless MAX taking into consideration who will be putting these things on their boats. People with "X" # of $, willing to give it away to go "Y" faster, and feel "Z" cooler than you in the end! haha


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## padean (Jul 5, 2001)

I actually just put in an order for a variprop 3-blade feathering prop. After looking as several options at Strictly Sail Chicago, I was impressed by the engineering and the new low-profile prop hub. I had planned on getting a Kiwi prop (which I still think might be a good prop), but the price of the Variprop was only a few hundred $ more. I am in fresh water, though, if that makes any difference to those worried about salt-water corrosion. Sorry I don't know much about the MAxi and Auto props other than seeing them in demonstrations.


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## christyleigh (Dec 17, 2001)

As has been mentioned the Autoprop is expensive. I put one on my Catalina 320 after a couple years and used it for 4 years happily. My Nauticat came with one and besides the feathering and Great Reverse its Auto Pitching is great for Motor Sailing.


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## Maine Sail (Jan 6, 2003)

*If you read..*

If you read the MIT prop study the Max Prop develops about 2 lbs of drag and the Autoprop about 9-10 lbs of drag. If the intent of buying a feathering or folding prop is to reduce drag then I think the Max Prop is the best choice..

Of course I chose a Campbell Sailer prop to have the lowest drag in a non mechanical prop..


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## padean (Jul 5, 2001)

*"If you read the MIT prop study the Max Prop develops about 2 lbs of drag and the Autoprop about 9-10 lbs of drag."*

Do you know if the props currently made are the same as the props tested in the MIT study in 1994? Several props were not even made then, and at least some of the props have undergone significant changes in the last 15 years since the tests were done.

(Disregard if there is a newer MIT prop study.)

Of course, we are talking about a slight difference in efficiency and drag, and much of the choice will probably come down to ease of use, convenience, and local experience with a particular prop.


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## Rockter (Sep 11, 2006)

$1400 to change a prop that works?


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## Maine Sail (Jan 6, 2003)

padean said:


> *"If you read the MIT prop study the Max Prop develops about 2 lbs of drag and the Autoprop about 9-10 lbs of drag."*
> 
> Do you know if the props currently made are the same as the props tested in the MIT study in 1994? Several props were not even made then, and at least some of the props have undergone significant changes in the last 15 years since the tests were done.
> 
> ...


Same 1994 study but the differences in these props externally from then until now is very slight. I just finished researching props for my own boat, and I would guess the Max still has one of the lowest drags for a three blade prop.

I looked at many including Autostream (HUGE HUB), Max, Gori, Kiwi Autopop and others. I also spoke at length with my local prop shop about repairs. They sell many different brands and for them the Max Prop has been the most reliable but still gets no cigar from Mike the manager. The had a total of four feathering/folding porps in house at the time for rebuilds/repair ranging from $500.00 to over 1k.

My reason for not choosing a floder/feather prop was reliability and the fact that they do not like to hit lobster pots which can literally sheer off blades (had one in house that had happend to). We have lots of lobster pots up here.. My own prop shop talked me into a prop they don't even sell..


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## padean (Jul 5, 2001)

*Feather vs fixed*

The other question I would have is why buy a feathering or folding prop if not racing. The difference in drag can be made up by chucking a few of those extras off the boat that haven't been used in several years, and a fixed blade prop is essentially maintenance free (other than cutting loose the tangled lobster pots and fishing lines). As Maine Sail described, these props are not always the most sturdy. A nice 2 or 3 blade fixed prop will nearly always perform better under motor, and will certainly last longer.


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## Maine Sail (Jan 6, 2003)

padean said:


> The other question I would have is why buy a feathering or folding prop if not racing. The difference in drag can be made up by chucking a few of those extras off the boat that haven't been used in several years, and a fixed blade prop is essentially maintenance free (other than cutting loose the tangled lobster pots and fishing lines). As Maine Sail described, these props are not always the most sturdy. A nice 2 or 3 blade fixed prop will nearly always perform better under motor, and will certainly last longer.


That is why I went with a Campbell Sailer... I don't currently race and prefer the reliability over the .1 knot..

The funny thing is that a Campbell Sailer three blade at 4 knots has the same drag as a 2 blade Michigan Wheel Sailer prop and only about 1.5 lbs more drag than Martec 2 blade folder. In higher winds 12+ the hull speed is slowoing me not my prop.

I don't hear folks talk about this much but folders/featehring props only really help in lower wind speeds. Once you hit hull speed.... In 13-15 knots I can tow my dinghy with the motor on and still hit hull speed so at that point I could have a 2X4 as a prop and still hit hull speed.


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## blt2ski (May 5, 2005)

Then again, folks that want to sail in area's with lower wind speeds, where it is harder to hit hull speed, will find that a folder/feathering prop will net you upwards of .5-1knot of boat speed in those lower wind ranges, ie less than 10 knots. Obviously if in a 20+ knot wind, the prop is not the worst thing for slowing the boat down! 

With that in mind, my boat came with a max prop, and the previous owner did report .5-1 knot gains in lighter winds! In Puget Sound where I am, in the summer we do get quite a few days with winds under 10 knots during the day. So if you want to sail more, faster etc, it really will not matter if you race or not, a folder WILL allow you to motor less!

Another prop option, is a Kiwi. An identical boat to mine north of me that races heavily, he mentioned he gained a bit more speed with a kiwi over having a max prop on the boat. ALong with a bit more motor speed at the top too!

overall, I am happy with the max prop that came with my boat!

Marty


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## josrulz (Oct 15, 2006)

I'm kind of in a similar position about where to go... My boat came with an old-style Martec 2-blade folding prop (no gears). It's in good shape, but once we splash the boat, I have a feeling I'll be unimpressed by it's performance in reverse, while being happy with the sailing performance. I'm also not thrilled about the potential reliability factor.

From my perspective, I'd hate to buy a replacement prop that would noticably slow me down sailing (I'm not racing, but like moving in lighter air on the Bay), but I'd like to be able to reliably back up when needed.

The Kiwi prop interests me due to the price point when compared to other feathering props, and I'd never spend the bucks for the others. 

My problem is that I don't really have a clear picture of the actual performance implications of my current Martec, versus a Kiwi, versus a 3-blade Campbell sailor. I know the pluses and minuses of each, but how noticable those differences are is something I can't really quantify. That makes the choice more difficult.


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## lancelot9898 (Dec 30, 2008)

I bought my boat new in 1985 (Tayana 37) and installed a 3 blade max prop. After some adjustment to the pitch after a year or so it is doing fine to this day. Everytime I haul out I repack the prop with grease which is somewhat of a hassle requireing another set of hands to get the blades properly lined up. I think the newer ones have a grease fitting. The nice thing about the pitch adjustment is that you can play with it to get the proper rpm on your engine. It is excellent in reverse and there is a slight ineffenciency in forward since the blades are flat and not curved as a fixed prop, but the difference is very hard to quantify.


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## j34035 (Nov 10, 2006)

Maine Sail said:


> That is why I went with a Campbell Sailer... I don't currently race and prefer the reliability over the .1 knot..
> 
> The funny thing is that a Campbell Sailer three blade at 4 knots has the same drag as a 2 blade Michigan Wheel Sailer prop and only about 1.5 lbs more drag than Martec 2 blade folder. In higher winds 12+ the hull speed is slowoing me not my prop.
> 
> I don't hear folks talk about this much but folders/featehring props only really help in lower wind speeds. Once you hit hull speed.... In 13-15 knots I can tow my dinghy with the motor on and still hit hull speed so at that point I could have a 2X4 as a prop and still hit hull speed.


You are correct that once you reach hull speed, a folding/feathering prop will no longer help your boat speed. Dont forget though, windward ability is a function of the lift/drag ratio. If you decrease drag or increase lift, you can point higher for the same boat speed. A folding/feathering prop will give you a few points toward the wind with no reduction in boatspeed. My 2 cents......
DD


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## Fstbttms (Feb 25, 2003)

The Max Prop is a robust, well-engineered piece of gear that does its job very well. The Autoprop has a nasty tendency to throw blades. Read all about it:

Autoprop?? - Cruisers & Sailing Forums


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## jrd22 (Nov 14, 2000)

We put an Autoprop on the last boat which replaced a three blade fixed. This was on a 34' sloop, 13000 disp. We noticed a large increase in light wind speed -app. .5+ knot. This allowed us to sail instead of motor more often in the light winds of summer here in the PNW. There was a huge difference in motoring efficiency and reverse power was amazing. There is also no prop walk, none. It made docking easy, and backing out even easier. We gained about 1 knot at the same rpm which allowed us to run just under hull speed without the noise of the engine at higher rpm. We put over 1000 hours on it over 12 years and never had a problem although I have read the thread provided above and wonder if something has changed. Seems like Autoprop would be out of business pretty soon if it was a widespread problem. The current boat has a fixed three blade sail prop, not sure if I'm going to spend the 4K for the Autoprop or not, I sure miss the ability to reverse in a straight line.


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## tomhuntdmd (Apr 7, 2008)

The Catalina 470 we bought two years ago came with an Autoprop and has served us very well. As stated, there is no propwalk. I couldn't tell you if it is port or starboard. Also, when the blades swing around, they give full thrust in reverse.

But to me the biggest advantage to the Autoprop is its ability to self pitch. This was discussed at some length on our C470 forum. This can result in fuel savings, especially when motorsailing. As the sails add speed to the boat, the blades dig in deeper, keeping the engine under a more proper load and RPMs lower.

For reference, we usually cruise at 2200 RPM at 7.2 kts in flat water, burning 1.08 GPH with a 28,000 lb boat (Yanmar 75 horsepower).

So far, we have had no maintenance issues, just grease and change zincs.


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## Valiente (Jun 16, 2006)

I am (finally) installing my VariProp this year. Long story, but I expect great things from it. As for "why", my steel full keeler will benefit from it under sail probably more than my fin keeler did with a Gori folder (and that impressed me), and the ability to have separate forward and reverse pitch settings that I can adjust with an allen key and a snorkel (in the water) makes it worth my while. Basically, I want to stop the boat and maneuver better than I can with a fixed blade, and I have seen most feathering props perform very well in this regard.


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## Shortman (Feb 12, 2006)

*Kiwi*

I've had it two seasons & like a lot. Less drag, way better reverse & forward than my previous two blade fixed. Lots less $$.


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## Rockter (Sep 11, 2006)

Buy a long-keeled double-ender, mark the prop shaft so that you know when the prop blades are vertical, and turn the prop so that the blades are in line with the keel.

On the point about "hull speed", drag always slows the boat. At higher speeds the fractional contribution of the drag from the prop drops off as there is so much drag from the hull shape, but the drag from the prop is steadily rising.

With a lot of wind around, you won't notice it much, but it will be there.

At very low speeds I reckon you won't notice it much either, as the vast majority of the drag will be from surface drag, and the prop, though an obstruction, does not wet much area. It obstructs (from form drag), but do you not need a decent bit of speed to see that one? There should be a good graph to plot in there somewhere?

Next time I am out in light airs I will try to turn the prop in line with the keel, and then perp to the keel, and see if it gets noticed. It should be a good experiment.


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## blt2ski (May 5, 2005)

Lat Nov I was returning from a Race south of me in Seattle, was heading north in 20-30 knot winds, full main and 155 up. Heard a thumping sound for a bit, figured out it was the prop, ie my max prop turning. At the time doing upper 6 to low 7 knot water speed. HullSpeed is 6.6 or there abouts, ie 24.5' WL. Put the trans in revers, thumping stopped, soon after gained some .5 to 1 knot speed, within a minute! Eventully as the wind piped up, we were doing low to mid 8's, even in to the 9's! 

While I understand the reason for a fixed like Main sail mentioned, crab/lobster pot issues, for many of us, the foler/feathering prop will net some speed, not matter the speed we are going, or wind speed! 

Marty


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## Valiente (Jun 16, 2006)

Rockter said:


> Next time I am out in light airs I will try to turn the prop in line with the keel, and then perp to the keel, and see if it gets noticed. It should be a good experiment.


It will indeed. The difference was so noticeable in light airs on my fin keeler when I switched to a folder that it went a long way towards persuading me to go to a feathering prop on my full keeler...that and the positive experiences of my friends with equally "primitive" hull shapes!

On the fin keeler, I noticed that the boat would accelerate better in puffs, would continue to ghost in very light airs that used to see it stop, and that going from a 12 x 6 two blade fixed to a 11 x 8 two blade folder dropped my "dead slow" from 2.5 to 1.7 knots in calm air, giving me more options in docking and maneuvering. The only downside was the slight hesitancy as the blades deployed, which I solved by a brief "gunning" of the engine to get the prop spinning.


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## crout (Oct 9, 2000)

Re: Folding/feathering props.
While it is true that the difference between a folder/featherer and a fixed prop is most apparent in light air and that hull speed is the limiting speed in heavy air, the real advantage lies not in an increase in speed, but in the increase in windward ability.
In most applications this amounts to 3-5 degrees per tack. This is 6-10 degrees improved angle to windward. A peek at a vector diagram will explain this. The wind in the sails produces a huge force roughly perpendicular to the heading of the boat. This force is opposed by the keel or center/dagger board which must operate at a slight angle through the water moving past it (leeway). When closehauled, which is the condition we're talking about, there is very little sail force left over to move the boat forward. Any drag removed is force freed to move the boat in the direction it is heading. This is why a clean bottom is desirable. A fixed 3 blade is roughly the equivalent of towing a peach basket.
I know gentlefolk never sail to windward, but consider the savings in diesel when you can make 5 knots and 5degrees better to windward in conditions in which you would previously have had to motorsail. Another condition worth thinking about is when deep reefed. In this condition any increase in windward ability results in a better ride. 
Of course if you are towing a dinghy all thoughts of sailing higher than a beam reach are out the window.


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## TSOJOURNER (Dec 16, 1999)

*Maxprop*

My maxprop came with my Pearson 419 bought used in 1992. 16 years of flawless performance with minimal maintenance and top notch customer support from PYI in Seatle (?) . What more can one ask ?


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## blt2ski (May 5, 2005)

If you want the honest truth, PYI is in Lynnwood, about 15 miles north of the city limits. 

They are good props.

marty


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## blfleno (Mar 17, 2003)

*Autoprop vs...*

I've had an Autoprop on a IP 40 for 4 years and have found it to be an excellent product. Bought it for it's ability to vary the pitch. Stopping/Reverse are vastly improved over the fixed prop. Boat speed is up about .5 k under sail. After initial install there was some vibration. Did some Speed/RPM tests for Autoprop. Sent it back to their factory they returned a corrected prop.(all on their dime). I know they changed design about 8-10 years ago to a greased bearing from a water lubricated one. Have not heard of blades "falling off" first hand. I did purchased an adapter to hold an off the shelf zinc as the AP Zincs are hard to find and expensive. You will also lose the prop walk, which on a long keel will make reversing at low speeds interesting. I sail Long Island Sound where there are lots of lobster pots. The keel, skeg, rudder setup that's on the IP40 is terriffic. I haven't wrapped up yet.

Bob Fleno
Thai Hot
IP40
HYC, City Island, NY


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## Volkhard (Feb 19, 2006)

I have an AUTOPROP on my IP 37 (1997) and love it. The prop came with the boat when I bought her 2 years but was interestingly never installed before. The PO had still the fixed 3 blade factory prop on. I had it installed right away and compared with other IP I sailed I like the "no prop walk" and the added .5kts in light air.

The only issue I have is the fairly expensive and IMHO badly engineered special zinc. This zinc is hollow and doesn't hold up at all. I have to find an adapter to switch to a better zinc. It's a shame the manufacturer of such as nice and sophisticated product didn't came up with a decent zinc solution. I can hardly believe the profit out of the zincs is that important (at the end it's not a ink jet printer where the money is in the cartridge). If you can afford it, I think the Auto prop is an excellent choice. I don't want to miss mine.


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## Valiente (Jun 16, 2006)

I can't recall the actual design of an Autoprop but if their zincs are rare and/or ridiculously expensive, how hard would it be to simply machine them from zinc bar stock? (Which I am assuming exists!). I just rechecked my chemistry memories and not only does it melt at only 90C more than lead (so it could be cast into molds), it is malleable at just above the boiling point of water, meaning it could be hammered on a small anvil if both were put in a medium heat frying pan!

I have had occasion to hand-work some aluminum bar stock and so on for backing plates, brackets and the like, and it's easier than wood in some ways.

I wouldn't hesitate to make my own prop hub zincs if it came down to tapping a small cone or putting a hole through it for a cotter pin.


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## Fstbttms (Feb 25, 2003)

Valiente said:


> I can't recall the actual design of an Autoprop but if their zincs are rare and/or ridiculously expensive, how hard would it be to simply machine them from zinc bar stock?


They're not _*that*_ expensive.



Valiente said:


> I wouldn't hesitate to make my own prop hub zincs if it came down to tapping a small cone or putting a hole through it for a cotter pin.


As previously mentioned in this thread, there is an aftermarket adapter available that lets you mount a standard American-style prop zinc on the Autoprop.


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## Volkhard (Feb 19, 2006)

*Autoprop Zincs*

As with everything, pricing is relative. The price for the Zinc itself with ~$25 seems reasonable, BUT they don't hold up at all.

They are nicely streamlined shaped as a cone, 3 holes for the plastic bolts and all but they are hollow. I have a diver cleaning the bottom/checking the zincs every 4 weeks in the summer and every 6 weeks in the winter. The Autoprop zincs is only good for about 2 month while all other zincs are holding up 6 to 9 months or more.

I guess if they would be more solid there would be more sacrificial material and they would hold up much longer. Compared in regard to the lifespan with other zincs for me the Autoprop zinc is at least 3x more expensive. I heard about bronze adapters available one screws to the back of the prop to be used with shaft zincs.

If anybody has experience with this and has a link for a source it would be greatly appreciated.


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## genieskip (Jan 1, 2008)

I put a three blade Max on my boat last year and love the thing. Little drag and good power transfer - a lot better than the Martec that was there before. I was seriously looking at the Autoprop but the guy in the boat next to mine last winter had one and he loved it except (according to him) when he hit a sharp chop and the blades refeatherd and the had a hard time getting going again. I have no idea if this problem is generic or specific to his boat, but it was enough to discourage me from getting one.


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## djodenda (Mar 4, 2006)

I wandered into the PYI (makers of the Max-Prop) factory a couple of months ago.

I found out something that might be of interest to you.

They sell used, reconditioned Max-Props.. They are about 30% less than new ones.

So, if you're thinking about buying one, you might call them up and see if they have a used one in the size you want.

David


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## Fstbttms (Feb 25, 2003)

Volkhard said:


> If anybody has experience with this and has a link for a source it would be greatly appreciated.


Autoprop Adaptor page


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## captmikem (Feb 28, 2004)

I have had a couple of Max props on different boats. I have had little or no trouble with them and I like the way they run, feather, and give extra power astern. I while ago I bought an HR 42 with a Max prop. It was well worn and at the first haulout I sent it in to be serviced. It came back looking like a piece of jewlery, and performed perfectly. It is easy to change the pitch at haulout. I have no experience with an autoprop.


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## Fstbttms (Feb 25, 2003)

captmikem said:


> It is easy to change the pitch at haulout.


An experienced diver can do it in the water for probably less money and certainly less inconvenience than a haulout.


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## lancelot9898 (Dec 30, 2008)

Fstbttms said:


> An experienced diver can do it in the water for probably less money and certainly less inconvenience than a haulout.


I disagee with that statement if you are referring to the max prop. Being both a certified diver and a max prop owner for the past 20 plus years, I would not want to change the pitch under water. In fact, I need an extra pair of hands when changing that pitch on the hard. It's difficult lineing up the blades to get them set into the exact groves. Other than that the prop has been great!


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## Fstbttms (Feb 25, 2003)

lancelot9898 said:


> I disagee with that statement if you are referring to the max prop. Being both a certified diver and a max prop owner for the past 20 plus years, I would not want to change the pitch under water.


Well, I disagree with your disagreement. I have installed, removed and repitched many, many Max Props with a 100% success rate, all of them underwater. In fact, if you were to call PYI and ask them for a diver to do such work in the Bay Area, they'd point you to me. They recommend divers all over the country that service Max Props underwater. For someone experienced and properly equipped, it's no big deal.

BTW, I have never lost a part. Even if I did, PYI have assured me they would Next Day Air a replacement at no cost.


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## cutterorient (Feb 22, 2009)

*fixed prop*

I bought a boat with a new ( 135 hours) engine, drivetrain, and feathering propeller. A very expensive type of prop mind you. I was excited ! no drag under sail, power thrust in both directions, all that jazz.

Never again. It popped the key twice, once in an extremely dangerous situation on a large river woth tons of commercial traffic, current, and no wind. That and damage to my hard working, no complaints rudder.

I replaced with the Campbell Sailor. It is made of a single piece of metal, produces gobs of thrust, much better balanced than any one with moving parts. I will never own a prop with more than one piece again. Oh, the campbell cost 1/4 as much as the prop it replaced.


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## TSOJOURNER (Dec 16, 1999)

*Kiwi Feathering Prop*

*If you happen to be in the UK, Kiwiprop have a stand at the Southampton Boat Show (11th-20th September 2009). They will be inside the Ocean Hall, at stand G10  *


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## philsboat (Oct 16, 2006)

A friend with a C & C 36 hit a piece of wood with his Maxprop and one blade stripped its gears.Insurance paid for a replacement so he changed to a Gori which seems a lot more robust.He was told you can't replace damaged parts in a Maxprop.

Phil


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## TSOJOURNER (Dec 16, 1999)

For those interested in Kiwi I had one fitted to my Feeling 36 when I bought her 18 months ago. As I've only sailed with this prop I can't offer any direct comparisons, but I can report two minor maintenance issues (or rather, good service issues). I can also say that the previous owner thought reversing on the old fixed two-blade prop was sometimes "interesting" and on the Kiwi I have found the boat delightfully manoueverable in both directions, so there is probably truth in the reduced prop kick argument.

Firstly at first year maintenanace my boat yard reported stailess steel pins were badly corroded (but not failed) - UK Kiwi agent immedately sent titanium replacements foc. I understand titanium pins are now standard.

Second, heavy vibration in gear last weekend pointed to a prop problem. My boatyard attended quickly and found one Kiwi blade "stop" missing; probably a rope snag had done it. I haven't knowlingly snagged a rope, although there was that strange hesitation in Loch Aline ... Again Kiwi have supplied the part overnight (and we are talking about semi-remote location) and all's fixed.

Added to the two impressively speedy parts, Kiwi were able to customise and supply the prop at very short notice in the first place, and I've had no reason to doubt or change the pitch settings.

So, 10/10 for (UK) service, and I accept that something with moving parts is going to be more vulnerable than a bronze cast. I love to think of those blades feathering when not in use.


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## rmorris001 (Aug 31, 2009)

Have a Max Prop on my 44 foot Bristol -- recently purchased. Surveyor suggested replacing it with a regular cruise prop. According to him I'd increase my RPM and have fewer problems, whatever those problems might be. Advise pro or con, please?


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## TSOJOURNER (Dec 16, 1999)

Love my maxprop. Installation was not that difficult (sawing off the end of the shaft was scary) and I can change the pitch when I pull it (I think I need a little more). I can now back into the slip!!!


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## rmorris001 (Aug 31, 2009)

Maxprop seems to be working fine for me, too. Believe I'll just stick with it.


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## Fstbttms (Feb 25, 2003)

rmorris001 said:


> Have a Max Prop on my 44 foot Bristol -- recently purchased. Surveyor suggested replacing it with a regular cruise prop. According to him I'd increase my RPM and have fewer problems, whatever those problems might be. Advise pro or con, please?


Sounds like your surveyor doesn't know his ass from a hole in the ground.


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## davmarwood (Jan 12, 2008)

*Max Prop*

We bought our 35' Beneteau in Oct. '07 and the PO had installed a MaxProp in '06. We used it all throughout the '08 season and also this '09 season with no problems. In the light air of the Chesapeake, I have noticed we can creep up and pass other similar boats. So, the reports of .5 knot advantage seem realistic to me. Reversing gives a moment of prop walk to port until sternway allows the rudder to affect the direction of the boat. Once sternway commences, it steers as well in reverse as in forward. Docking stern-in is a snap. I have no experience with other folding/feathering props, so I can't compare, but I am totally satisfied with our MaxProp,and would recommend it to anyone wanting a foldng/feathering prop. Cost might be an issue, as these items are not cheap. On our boat the list is around $2800 for one of these props before installation. Fortunately for us, the PO absorbed this cost. One note of caution is that these props need annual service as recommended by the manufacturer. If they are not serviced as recommended, they will fail to perform properly.


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## lancelot9898 (Dec 30, 2008)

davmarwood said:


> . One note of caution is that these props need annual service as recommended by the manufacturer. If they are not serviced as recommended, they will fail to perform properly.


I too like the max prop having installed one on my current boat back in 1985 and it's still doing fine. I routinely haul out about every three years here on the Cheaspeake and at that time I repack the prop with the proper grease and replace the zinc. Sometimes I do dive on the boat to change the zinc after about a year and a half, but the yearly service is something that I have not done for the past 24 years. FWIW I also paint the prop with bottom paint which is not recommended although I do prep it first with the Interlux underwater primer. Even though this has worked for me, your results may very and yearly maintenance if fine.


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## rmorris001 (Aug 31, 2009)

*Maxprop*

Thanks for the information and the tips. Very helpful. I'm keeping the Maxprop. It hasn't caused me any problems so I have no complaints.


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## Nelsoncw (Dec 6, 2006)

I have an Autoprop on my Catalina 42. AB Marine had rebuilt the prop in 2007. In May of 2009 and 225 hours later a blade came off. Buntons Marine replaced the blade for $1500. I had it lubricated every six months. I am always in deep water. It never touched anything but saltwater. I only go to Catalina and back. Other than the lost blade there was not any evidence of damage or distress.

At the time Steve Armitage of AB Marine told me that losing a blade was a rare occurrence and that he did not have an explanation for why the blade fell off. David Sheppard of Brunton's Propellers Ltd, told me losing a blade is an “an exceptional case”. Contrary to their comments the prop has been subject to a recall for lost blades. If you search other support groups and blogs you will find many others that have lost Autoprop blades. It demeans their credibility to say otherwise. 

Although I enjoy the performance of my Autoprop my experience with AB Marine and Brunton's Propellers has been extremely disappointing. They are unwilling to stand behind their expensive product. In all their replies I feel like I am hearing from a politician trying not to give a straight answer.


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## RichH (Jul 10, 2000)

If you 'shift' from reverse to forward a lot, as for the need to 'back and fill', etc. into and out of a slip, etc. the Max prop will eventually loosen at the blade roots and the blades will then begin to 'wobble'. Obviously with a Max you must/should idle 'all the way down' when shifting; but, the need to sometimes shift quickly will 'hammer out' and loosen the blade roots / blade spindles.


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## Nelsoncw (Dec 6, 2006)

*Autoprop*

I have an Autoprop on my Catalina 42. AB Marine had rebuilt the prop in 2007. In May of 2009 and 225 hours later a blade came off. Buntons Marine replaced the blade for $1500. I had it lubricated every six months. I am always in deep water. It never touched anything but saltwater. I only go to Catalina and back. Other than the lost blade there was not any evidence of damage or distress.

At the time Steve Armitage of AB Marine told me that losing a blade was a "rare occurrence" and that he did not have an explanation for why the blade fell off. David Sheppard of Brunton's Propellers Ltd, told me losing a blade is an "an exceptional case". Contrary to their comments the prop has been subject to a recall for lost blades. If you search other support groups and blogs you will find many others that have lost Autoprop blades. It demeans their credibility to say otherwise.

Although I enjoy the performance of my Autoprop my experience with AB Marine and Brunton's Propellers has been extremely disappointing. They are unwilling to stand behind their expensive product. In all their replies I feel like I am hearing from a politician trying to avoid giving a straight answer.


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## Fstbttms (Feb 25, 2003)

Yeah, I pretty much got the gist of your rant the first three or four times you posted it on at least two different sailing forums.


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## sailingdog (Mar 19, 2006)

Nelson

Thank you for spamming sailnet with what is basically the same post in FIVE DIFFERENT PLACES.


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## Jeff_H (Feb 26, 2000)

Guys, 

While I understand the basis of your comments, I don't think that it is unsual for someone to post the same message to a number of threads and forums when that person believes that the point is relevant to the discussion at hand. I know I have posted the same post with my concerns about the motion comfort index, and capsize screen formula on a bunch of different forums and discussion. 

Respectfully,
Jeff


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## sailingdog (Mar 19, 2006)

One minor difference, you don't generally join a forum to hammer away on a specific vendor. ALL OF HIS POSTS are on this one topic, where yours tend to cover a bit wider a cross-section of sailing subjects. 


Jeff_H said:


> Guys,
> 
> While I understand the basis of your comments, I don't think that it is unsual for someone to post the same message to a number of threads and forums when that person believes that the point is relevant to the discussion at hand. I know I have posted the same post with my concerns about the motion comfort index, and capsize screen formula on a bunch of different forums and discussion.
> 
> ...


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## overbored (Oct 8, 2010)

If a blade can off and it did not damage any part of the hub then the only thing it could be is human error. the nut was not tight and the lock ring was not set when the prop was rebuilt. what the rebuilder says he does not know why only one of three blades came off and yet the threads on the shaft are ok?


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## jrd22 (Nov 14, 2000)

Overbored- my thoughts also.


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## Fstbttms (Feb 25, 2003)

overbored said:


> If a blade can off and it did not damage any part of the hub then the only thing it could be is human error.


The human error is in the design of Autoprop. These things have a long history of losing blades.


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