Most reliable feathering propeller

[HankOnthewater]

I have no idea what the most reliable feathering prop is. I recall a test that Practical Sailor did a few years ago. Can't remember the outcome. Hmmm, some could diagnose me with onset of dementia

The problem with these kind of posts, it fails to define a word; in this case “reliable”. Therefore we have nothing to measure it by. Hence we get mostly opinions. Good onya for the owner who could report a value of 1271 hrs!! And then as post #7 points out, the marketed or perceived performance differences are small, could be in the realm of single digit percentages.

And even regarding longevity / length of service, before rebuilt /overhaul:
- a prop that is greased every haulout, or disassembled, cleaned and greased will last longer than the one that is not
- a prop that has one damaged blade will not last long either (and will vibrate)
- the skipper who often changes gears quickly from high revs forward to high rev astern, will likely reduce the lifespan of that feathering prop (even some brands tell us that fast gear changes are no problem)

To me “reliable” means: years of use it was intended for, with the manufacturer’s prescribed maintenance, without a need a rebuilt, or special kits. Then we can argue how for many years. Even then, years sitting in a marina, or years sailing around the world?

If a prop costs $5k Oz(for argument’s sake), or most things with this kind of price tag, then I would expect a minimum of 10 years of active use, preferably 20 years.

BTW, looking at invoices that came with my boat, the Max prop was fitted in 1993, still there, in good condition, and no invoices or details on any rebuilt. Engine hours (since 1993) around ~7000 hrs, sailing hours??? Who knows, don’t have all the logbooks. And if the props falls off tomorrow….. then I will ask the question here what the best one is: “best” being a combination of: performance, ease of maintenance (including altering pitch), ease of procuring parts like anode, ease of fitting, ease of long life without rebuilt, ease of repair, and finally price.

[chouliha]

We have a max prop we installed 25 years ago and has close to 5000 hours on it. Never any issue.

There is some slop in it now and it should be serviced. Easier said than done when the prop shop is 5k away from our location

[stormalong]

I have had a Maxprop three blade classic on my boat since it was new - 1985. I have had it overhauled twice. Once by Maxprop and once by a marine propulsion engineer in New Zealand. I have had two engines and two transmissions but only the one Maxprop. It now has about 10,000 total engine hours and over 130,000 sailing and motoring miles on it.

This one was so old that it had to be disassembled to be greased until I saw a newer one that was drilled for Zerc fittings. I did that mod and it has saved at lot of time and cursing when servicing. The original manual I had was in Italian - That's where they are made.

Boat is being hauled on Tuesday after three years so I will know then if it needs another overhaul.

[Tumblewoods]

Thank you all for the valuable replies. All good points.
I understand the props all require maintenance and tend to agree that a 1200 hr rebuild is not what I would call reliable. (If maintained). Propspeed failing after 3 months is not reliable !
For General interest what I think I have discovered today is that when I sent my kiwi props off to get maintained in January they replaced the blades with a bigger set. The saildrive reverse ratio (lombardini) combined with only 30hp and the bigger blades meant there was insufficient torque to get the blades to reverse.
So my kiwi props may well be reliable but the new blades are the incorrect size.
I’ll replace the blades and then see how I go. I may not need a new set after all 🙏
Tim

[daletournier]

I had a kiwi prop on the previous boat. The reverse issue can be solved by regular greasing. I had a hookah therefore would grease regularly while in the water.

I have a maxprop on my current boat, seems to be very robust and I've experienced no issues. It has more prop walk than I'd like, but you learn to use it. I also like that I can adjust the pitch while in the water as well as grease it while in the water.

[bgallinger]

I have had a Kiwi prop for 5 years now. It works very well, but I have two concerns. First, I believe I am losing almost 1 knot of speed when motoring, but the prop blades may need a pitch adjustment. Second, the mud, sand and grit in the ICW clog up the feathering to the point where reverse is not attainable.

[a64pilot]

Prop walk is a good thing, my fixed prop has loads of prop walk and once I got used to it, I called it my poor man’s bow thruster.
My Autoprop has zero as in no detectable prop walk at all. To some that’s an advantage, but I miss the prop walk, made docking and turning in confined areas much easier.
Maybe if I had a bow thruster then I wouldn’t like prop walk?

[mikereed100]

Originally Posted by daletournier

I had a kiwi prop on the previous boat. The reverse issue can be solved by regular greasing. I had a hookah therefore would grease regularly while in the water.
.

My experience as well, although not always effective. If I remove the props, take them apart and pack them with grease I will get a month or two of trouble-free reversing. I suspect that with smaller engines, mine are 29hp, the torque is not enough to overcome the resistance of the blades. I have found that "tapping" the gearbox into forward then immediately into reverse aligns the blades and prevents stalling, but I suspect this is not good for the gearbox and causes some delay when reverse is needed.

[Greg Mason]

If you follow the directions of the manufacturer, you won't be slamming it in reverse just after you put it in neutral. Let the shaft slow down or stop it, then reverse to taper the blades. There are moving parts. Treat it right and you won't be rebuilding at 1200 hours, especially if you grease it like the manual says.

[aquafacts]

Yes ! Yes ! Yes ! to Autostream - They have industrial plastic bushings on inboard and outboard end of each paddle that can be changed on site extremely easily and cheaply - no need and expense to send it back for rebuild. Stainless steel housing. Can be greased underwater as nipple is on end cone and zerk stays put (unlike Max that you have to insert zerk fitting and remove) O-rings on each paddle to keep grease in ! No fooling around with dots and letters and needing several peoples hands to set pitch while on hard as Autostream has independent external adjustment that can be done easily underwater. Check the pricing - you will be very pleasantly surprised.

There is a BETTER way !

[George DuBose]

Yachting Monthly did a review a few years ago of folding and feathering props.

Flex-o-Fold three blade and two blade were high in the ranking as I recall.

I have been using a two bladed FoF and have no problems maintenance-wise, my prop walk in reverse is less than with the two-bladed fixed prop I had and I didn't lose any boat speed while motoring.

I also think that a folding prop is less susceptible to snagging lines, etc.

[verb88]

very happy with the j-props my boat came with

[fstbttms]

Originally Posted by aquafacts

No fooling around with dots and letters and needing several peoples hands to set pitch while on hard as Autostream has independent external adjustment that can be done easily underwater.

Not only can ANY Max Prop be repitched underwater, but there are several models that have external pitch adjustment features.

[fxarcher]

I would love for someone to explain the advantages/disadvantages of a Hundested propeller system versus Autoprop.
I know Hundested (Denmark) starts somewhere around 150HP and does not require a reduction/reversible gear when coupled to low RPM engines.
Thanks

[singlespeed]

I found the Kiwi props to be very reliable and no issues when in reverse on a Lagoon42TPI. If the stern walks on a catamaran, with these, contact Kiwi directly for help. I switched out from large 3 blade fixed props and lost about a knot of motoring speed, but gained over two knots of sailing speed. If you forget to drop the transmissions into reverse when sailing, the feathering aspect keeps the drive shaft from turning.

In the warm Caribbean waters, diving on them monthly when at anchor, with a stiff plastic brush kept them barnacle, weed and slime free. Applied Propspeed at the original installation, but found the composite blades shed the paint really relatively quickly. Easy to lube underwater. Once had to replace two broken blades while at anchor; very easy with only a single Allen wrench required.