SO 43DS - Max Prop Questions

[wheelsucker]

Hi,

We're in the process of purchasing a 43DS/56hp/standard keel boat with a folding prop.  I've seen a few threads on folding/feathering props and fuel consumption but have the following questions regarding feathering Max Props on a 56hp 43DS:

a.  Can anybody comment on their 3 blade Max Prop?

b.  What size & pitch do you have, what average RPMs/speed do you cruise at and what is is the max RPMs you can achieve (I won't ask about speed)?

c.  Any comments about maintenance and/or longevity in salt/brackish water?  We'll be using it the Pacific Northwest to start.

Unhappy with the folding 3 blade - max speed and max RPMs (significantly overproped).

Thanks in advance.

[chuckr]

I do not have a Max prop but a Brunton Prop that i am in love with as is my DS40.  I generally cruise at about 1,500 - 1,800 rpm with a 56 hp yanmar.  I get about 1/2 + gallons per hour depending on how many rpm.  I think the prop is 18" but not sure. 

No problems in salt water or anything else.  Until an issue i had over 55k nm on the prop as i am a full time liveaboard cruiser.  The issue i had was i picked up a fishing net crossing the Atlantic and it got past the shaft line cutter and wrapped and took off one of the blades.  In retrospect i think that was good (a bit expensive) because it was 15 days of winds 25gusting 35 with seas on the stern of 12-15ft and for 5 days a 10 ft swell just aft of the beam -- Yea it was a really bad trip but if the net had wrapped on a standard prop i may have towed it a long way and done a lot of damage -

I have a new Brunton currently sitting in my forward berth waiting for a haul out and i can not tell you how much i dislike the fixed prop.  way to much fuel consurmption and start up is really slow and backing is a trick.  Love my Brunton. 

[MartyB]

PYI the US distributor is in Lynnwood. call them to find out what you should have on your boat. I know of at least three of us locally with max props on different sized Jeanneaus, and no one has a complaint about them. Any of the local shops can and will install one for you. Be it CSR, Seaview, Marine Servicenter, Gig harbor marina, to name a few that can do this.

One of them are people I know from local YC with a 43DS they keep in Everett. Gained sailing speed, better maneuverability etc

marty

[MartyB]

Now that I am rereading, you have a "NEW" one coming to MSC. just have them put one on. I'm positive they will know which one to install.

Marty

[ania]

Jeanneau 51, 20 x 15 RH 35mm shaft.
Fixed pitch $4750.00 US
Love it.

[wheelsucker]

Thanks for all the replies.  We're trying to figure out the best way to solve are over propped condition short of going back to the 3 blade fixed.

[rene460]

Hi Wheelsucker,

We don’t have a Maxprop, but the one we have is very similar in principal.  I would suggest that you go to the Maxprop website and read up on it.  

You did not say what you mean by overpropped.  What is the rated maximum continuous speed of your engine, and what rpm do you get at wide open throttle?  My Yanmar mechanic recommends that the engine should be able to achieve around 10% above the rated maximum speed at wide open throttle, so I use this as the definition.  Some forum members prefer sightly overpropped by this definition to give better engine load and thrust at more typical cruising rpm.  You need these figures for comparison if any adjustments are made.  It is critical that the prop is really clean for this test.  I have found by experience that even one small barnacle on one blade will severely limit your max engine revs.  Dive to check it, or get a diver who offers in water boat cleaning to do it for you.

If it is a feathering propellor, as I understand it, the pitch is adjustable, another similarity with my Autostream.  I am not sure about the folding ones.  Pitch adjustment is best done out of the water, you can’t drop the spanner or anything that way, or at least, it will be easier to retrieve if you do.  If you don’t have the documentation, it may be on the website, or use the “contact us” facility to ask them. They will also be able to tell you the recommended prop for the boat, and what they could do if you really have the wrong one.

Many forum members have the Maxprop and generally seem satisfied as far as I remember.  I suggest that it might at most need a pitch adjustment.  Mine has separate adjustments for forward and reverse, so check for that.

As for cruising rpm, ask twenty sailors and you will get at least thirty answers.  Engine manufacturers recommendations generally involve something like “above 80% rpm for at least 80% of the time“.  But many people prefer lower rpm for fuel economy and noise considerations.  Having a turbocharger adds another criteria as has already been mentioned.  I suggest keep the turbocharger happy, and get the engine hot often enough to keep it clean as a starting point.

There are many threads in the archives of this forum on the topic, and well worth spending a few quality hours reading during winter evenings as the topic is timeless.

I hope that helps

rene460

[zaphod]

Don't discount folding props just because someone mismatched the one you have. Folding props have a lot going for them. They are more efficient than feathering props in forward, they have less drag under sail, they have less propwalk, they won't pick up weed or rope under sail, and they are lower maintenance than feathering props. Granted they have a bit less bite than feathering props in reverse, but you just have to use more rpm.

I bought a Flexofold for my boat last year and I love it! I actually saw a speed increase over the fixed prop under power, and of course a huge increase in sailing performance.

Flexofold is an OEM supplier for Jeanneau, so if you tell them your boat, engine and transmission model numbers they will match up the right prop. It cost me thousands less than a Max prop.

This article breaks down the different props really well.

www.yachtingmonthly.com/gear/folding-and-feathering-propeller-test-29807

[alenka]

Hello Wheelsucker,

We have a 2004 43DS (75HP engine) with a 3 blade Variprop feathering prop.  Although the original fixed pitch prop is in the locker for emergencies I have never sailed the boat with it attached so I cannot offer any comparison comments.

I have always thought we were a little under-propped as we can easily reach max RPM without problem.  Like others I would prefer to be over-propped rather than under.  High RPM is a bit noisy with vibration.

The Variprop is adjustable via a few screws. This can be performed either in or out of the water. The latter requires a diver. Our maintenance organisation have declined to do the job as their divers have no experience of Variprop and they would hate to make things worse.

We have investigated the vibration aspect quite thoroughly and the internet seems to suggest that some folding/feathering props can give rise to this. All other aspects of our engine installation such as prop shaft alignment, engine mounts, etc, etc., are all good.

The 43 DS is easily pushed along and we hit 5 kts at low engine RPM but this is not good for the engine and turbocharger which prefers to be worked a little harder.  

Last year I completed a 1,000nm cruise and kept records of fuel burn/speed/RPM settings. The findings may be of interest to you, but bear in mind every boat is different so don't assume they are definitive for the model.  The link is here,

jeanneau.proboards.com/thread/7746/real-world-fuel-burn

[buddyseattle]

We have had a Max Prop for 9 years on our boat.

It has been great. PYI as Marty suggests is a great vendor. With assistance of PYI, we identified the right pitch to start with, and it was right on. We've played with the pitch, but have come back to the original setting.

It works as you would expect and PYI is exceptional on service. Service is important to get the max life out of it. We have has it serviced once, after 7 years of use (about 800 hours) by PYI. They also cleaned and refinished it so it's as good as new. This service isn't trivial, as they break it down, replace parts and restore to new. You'll also want to have your diver grease the prop when they dive on it for cleaning, zincs, etc.

We cruise at about 2300 RPM and get about 6.5 Knots with a full boat.

Reverse works not quite as well as a fixed prop. But once you get used to it, it is great. We do bursts of power and we have very little prop walk as result. There is plenty of power if you need it in reverse.

If you follow instructions, it folds without fail and added about .6Kts to speed under full sail.

I would call them and talk about all your questions, they are pretty legit.

Good luck!

[wheelsucker]

Thanks to all for their replies - I can sense this board will be super helpful in the coming years as we deal with various issues on the boat.

Alenka - I did read your real world fuel burn thread with great interest but other than one owner from NZ, no one commented on what the 56hp engine could achieve.

To answer Rene460 the engine is rated for 56hp at 3800 rpm.  At WOT with the folding prop, it only achieved 3100 rpm.  When we hauled it for the marine survey the prop was not clean (but no barnacles).  700 rpm difference seems pretty significant and we have a question about how fast the boat can go (conditions at sea trial didn't allow for an objective evaluation).

Having said all that, sounds like Max Prop is a good alternative for us.

Cheers!

[buddyseattle]

Good luck.
You can find data on HP and Burn rate for engines online. If you have the Yanmar 4JH4, this is the curve for it.
www.yanmar.com/media/global/com/product/marinepleasure/sailBoatPropulsion/catalog/Yanmar-4JH4-TE-LR.pdf

3800RPM seems like a lot, but I am no expert. Our Max is 3200 on our 3JH.

[wheelsucker]

Thanks Buddy.  We have the naturally aspirated 4JH3E and found than Yanmar power curves for that model.  I could be wrong but the curves seem to say that your 3JH3E also achieves max power at 3800 rpm.

Attachment Deleted

[alenka]

We can certainly get to 3,800 RPM which isn't comfortable noise wise but maybe that is just me.  We passage plan at 6.5 kts which is easily doable under sale or power and should be very achievable with your engine.  The bigger engine will not improve the boats top speed which is a function of hull but it will help to keep speed when pushing against bigger seas.

What RPM do you set to achieve 6.5 kts?

A new prop is a big expense you want to make sure the benefits are worth the cost.

[wheelsucker]

Alenka,

We haven't taken possession of the boat yet (still a few weeks away).  I understand about the hull speed and what the 56hp engine should be able to do under most conditions.  As I indicated in a prior post, conditions for the sea trial were not optimal so we didn't get a good feel for the cruising speed/different RPMs.  If I were to guess (and it is just that), I think 6.5 knots is about 2500 - 2800 rpm.  Sea trial captain didn't let us do much motoring due to traffic - as I said, less than optimal.  We had about 7.3 knots SOG with about 12 knots of wind when sailing, so I know the hull speed is decent.

[zaphod]

Jun 30, 2020 3:21:39 GMT buddyseattle said:

Good luck.
You can find data on HP and Burn rate for engines online. If you have the Yanmar 4JH4, this is the curve for it.
www.yanmar.com/media/global/com/product/marinepleasure/sailBoatPropulsion/catalog/Yanmar-4JH4-TE-LR.pdf

3800RPM seems like a lot, but I am no expert. Our Max is 3200 on our 3JH.

Yes, we have a 3jh4 in our 39i, and the max engine speed is 3200rpm. We cruise at 7.5kts @2500rpm, and get up to 8.5kts @3200rpm with our Flexofold.

[zaphod]

Jun 26, 2020 22:10:11 GMT wheelsucker said:

Hi,

We're in the process of purchasing a 43DS/56hp/standard keel boat with a folding prop.  I've seen a few threads on folding/feathering props and fuel consumption but have the following questions regarding feathering Max Props on a 56hp 43DS:

a.  Can anybody comment on their 3 blade Max Prop?

b.  What size & pitch do you have, what average RPMs/speed do you cruise at and what is is the max RPMs you can achieve (I won't ask about speed)?

c.  Any comments about maintenance and/or longevity in salt/brackish water?  We'll be using it the Pacific Northwest to start.

Unhappy with the folding 3 blade - max speed and max RPMs (significantly overproped).

Thanks in advance.

Have you considered that there may be a other reason the boat does not reach max rpm? It could be a governor issue, or just a poorly adjusted throttle cable.

[alenka]

Hell again. 

You don't say how far advanced you are in the purchase... Have you parted with a deposit and/or committed to the purchase, or are you still in the negotiation phase?  As you use the term 'sea trial captain' I am guessing you are based in the USA??  If so I cannot comment on the buying procedure that is the accepted norm there.

Here in the UK and many parts of Europe (Germany being a bit of an exception) you may be offered a sea trial by the seller/broker prior to putting down a deposit but it would not be unusual to ask for a second trial to be conducted by a qualified surveyor as part of placing a deposit.  In my case the sea trial and survey was done all at the same time and was conduced by a surveyor with the broker in attendance. Basically while the latter was trying to sell me the boat the former was looking for anything and everything that could be wrong with it.

It is not unusual for the surveyors report to be used for negotiation on the asking price. 

Have you had a professional survey done and what were his/her comments on your concerns?

I make these remarks only because there a few that come to this forum as first time a buyer/sailor and are unfamiliar with the best way to get the right boat and the questions asked by one person get answers that are of benefit to many others. 

Incidentally, I used a surveyor who worked his way up through the ranks at Sunsail from being hands on engineer/skipper to a very senior position before qualifying as a surveyor and starting his own business.  Sunsail have many Jeanneau models in their line up and the 43DS was included in their fleets worldwide. He knew the model well, how they should perform, what could break on them and how to fix them.  His report ran to 29 pages.

It is wise to pick a good rather than a cheap surveyor. I did come across one who listed an ignition key as being faulty because the diesel engine didn't stop when turned off!  How anyone can claim to be an expert when they have never heard of a cut off button is a bit unique.

[wheelsucker]

Thanks again for the replies and ideas contained within them.

Zaphod - engine surveyor ran it up to 4000 rpm WOT out of gear, so I believe that addresses the governor & throttle cable question.  Let me know if you think that is incorrect.

Alenka - I believe both the engine and marine surveyors were among the best available in the area.  Both seemed very knowledgeable & experienced (both over 60) and gave pretty detailed explanations both verbally and in their reports.  As far as I can tell, they both did their very best to identify issues that could impact us as future owners including the significant shortfall between RPMs at WOT and as spec'd by Yanmar.  We're proceeding with the deal and will most likely reprop with a Max Prop and play with the pitch if required.  After we take delivery I'll be back to this thread with updates with our findings.

Thanks again for all the input.  Take care and stay safe.

[alenka]

Wheelsucker,

Hope you enjoy your 43DS as much as we have. Our 8th season and still love it.