Propeller gear for sailing

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Nov 18, 2010
3
Hunter Passage 450 Houston, TX
I have a 1999 Hunter 45' center cockpit sailboat with a model 4JH2-HTE Yanmar 76 hp engine.

Should the transmission be in "neutral" or "reverse" position while sailing?

When I have the transmission in "reverse" and later put it in neutral, I cannot move the transmission to neutral. What should I do?
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
I have a 1999 Hunter 45' center cockpit sailboat with a model 4JH2-HTE Yanmar 76 hp engine.

Should the transmission be in "neutral" or "reverse" position while sailing?

When I have the transmission in "reverse" and later put it in neutral, I cannot move the transmission to neutral. What should I do?
Neutral, not reverse.
 
Dec 13, 2010
12
Hunter 41 Marina Del Rey
Significantly lower drag will be achieved with the prop stopped. Reverse is better as it locks the shaft and keep the prop from turning. You also reduce wear and tear on the shaft stuffing box and gear case if you keep the shaft from spinning freely while sailing.

I have a 2005 Hunter 41 with a Yanmar 50hp and I too have noticed that once in reverse, you can't shift back into neutral. I suspect this is due to the way the gears are cut and the rotational pressure on the shaft. Don't force it!! You will just stretch the shift cable, damage the linkage and the shift mechanism in the gear box.

Its ok to start the engine with it in reverse. Just make sure that the shift lever is at the idle detent (in reverse). Once the engine is running you will easily be able to shift out of reverse.

The better solution would be to install a MAX prop from PYI, Inc. I have had one on my H41 since I purchased it and it worked great. Provides an easy 0.6 to 0.8 knot of increased speed! I wouldn't have a sail boat without one. I see owners investing in expensive sails and other hardware all in an effort to eek out another fraction of a knot when all it takes to make a big improvement is a feathering propeller.

I love my MAX prop - haven't had a lick of trouble, it has proven to be very efficient and it always puts a smile on my face when I cruise past a Beneteau :)
 
Jun 4, 2004
1,071
Hunter 410 Punta Gorda
I just completed research on props and found information that indicated if the prop free wheels there is less drag than if fixed (in reverse). Frankly I can't stand the wining if it free wheels. I was really doing research to decide if I should install a 3 blade fixed, folding or feathering prop. I have decided to go with a 3-blade Flex-o-fold. There are several factors to consdier and for me, this prop has the best ratings in the areas I am intersted in. As for price it is middle of the road for folding/feathering props.
 
Dec 2, 1999
15,184
Hunter Vision-36 Rio Vista, CA.
I have also had the same problem with moving the shifter from Reverse to Neutral after sailing. My solution has been to start the motor in reverse and it pops right into neutral.
 
Dec 13, 2010
12
Hunter 41 Marina Del Rey
I just read the British Yachting Monthly, May 2009 test report on feathering and folding propellers and discovered that according to their test data, a freely spinning prop will cause half the drag of a locked prop. So much for an old salt's tale that so many of us have been told.

As for the 3-blade flex-o-fold - based on the test results it seems like a pretty decent propeller for a folding design.

Based on this information I would amend my advice to leaving the transmission in neutral. Of course you will want to make sure that a freely spinning prop shaft doesn't cause any harm to your transmission.

One thing I noticed on my H41 is that after shutting down the engine while leaving the transmission in forward gear, the prop shaft will continue to spin freely, driven by the prop. Even though I have a MAX Prop, at low speeds it won't completely feather unless the shaft is locked. When I originally got the boat, I was surprised to discover that the prop shaft will rotate freely while in forward gear after engine shut down. Clearly, the Yanmar 50HP engine trans is equipped with a Sprag clutch - a preety fancy feature by my estimation for what I would have thought would be a simple transmission. This is why I do shift into reverse - so that the MAX Prop will fully feather. After that the shaft no longer wants to turn.

I'm curious to know whether others have the same sprag clutch 'feature' on their transmissions.
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
I have also had the same problem with moving the shifter from Reverse to Neutral after sailing. My solution has been to start the motor in reverse and it pops right into neutral.
Steve,

This is why Yanmar strongly suggests not using reverse..

The thread on this MSA is here: A Definitive Answer From Yanmar

I personally spoke with their tech support and was told this applies to ALL marine transmissions on sailboats of all ages.
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
When I originally got the boat, I was surprised to discover that the prop shaft will rotate freely while in forward gear after engine shut down.
This is pretty bad for the gear box. While Yanmar advises against reverse you'll do less damage in reverse than leaving it in forward and letting the shaft spin as the clutches are actually "slipping" or grinding on one another as opposed to locking up.

Many gear boxes have been ruined from shutting down in forward. With the Max Prop you can shut down in neutral then switch to reverse to feather the prop and then move it back to neutral.
 
Nov 18, 2010
3
Hunter Passage 450 Houston, TX
Yanmar customer support strongly suggests putting the engine in "neutral." With engine in neutral, I can hear the driveshaft. Frankly I don't know if Yanmar's recommendation is best, or if I should let it run in neutral and experience wear and tear. I am confused.
 

Rick D

.
Jun 14, 2008
7,132
Hunter Legend 40.5 Shoreline Marina Long Beach CA
Yanmar customer support strongly suggests putting the engine in "neutral." With engine in neutral, I can hear the driveshaft. Frankly I don't know if Yanmar's recommendation is best, or if I should let it run in neutral and experience wear and tear. I am confused.
Don't be confused; follow the manufacturer's recommendation and leave it in neutral if you have a fixed prop. Consider a feathering or folding prop for the future, and the issue disappears (to be, of course, replaced by others). With a folding or feathering, you can shift into reverse to fold or feather the blades then shift to neutral.
 
Oct 10, 2008
277
Catalina 445 Yorktown
IMHO do what works on your boats setup (after the one year Yanmar warranty expires). After that, you're on your own anyway. While I'm well aware of Yanmar's MSA to sail in "neutral", I'm really suspect of their motives as they don't explain their rationale. Could it be that if the prop hits something or wraps around a rope, etc. that the sudden jolt could damage the transmission if it were in gear? Seems reasonable if that's Yanmar's concern - but they don't say. On the other hand, locking the throttle in reverse does save wear/tear on the cutlass bearing and shaft/transmission and that expense is clearly the boat owners. I'm one that sails with the transmission in reverse - I don't like the noise of a free-wheeling shaft and my Shaft Shark cutters are ready to cut any floating rope I might encounter. Again, after the warranty - it's your dime anyway!
 
Nov 18, 2010
3
Hunter Passage 450 Houston, TX
Thank you all for your wonderful help. I'm going to follow Yanmar's recommendation of "neutral."
 
Dec 1, 1999
2,391
Hunter 28.5 Chesapeake Bay
While I know the subject of leaving the transmission in neutral or reverse while sailing has been hashed over a lot, I've sailed boats with inboard engines for a lot of years and always locked the transmission in reverse. I have never had a transmission problem as a result. So, I only have a database of one. But I also know a lot of sailors who do the same thing and have never heard of one who had a transmission problem as a result. My main concern with a freewheeling prop while sailing is unnecessary wear on the entire drive train. As a cruiser, I really don't care about the minor increase in drag when the trans is locked in reverse. When I was a serious PHRF racer, I made a mark on the coupler to indicate when my 2-blade fixed prop was lined up vertically with the keel and then locked the trans in reverse to minimize drag.

While Yanmar may recommend leaving the transmission in neutral when sailing, (1) I would like to read or hear their views of the additional wear this causes, and (2) I'd like to read or hear what the makers of the transmission have to say about this issue as Yanmar doesn't make transmissions, I believe. Finally, if any one out there has a credible story about how his/her transmission was specifically damaged by locking it in reverse while sailing, I would hope they would post it here.
 
Feb 6, 1998
11,667
Canadian Sailcraft 36T Casco Bay, ME
But I also know a lot of sailors who do the same thing and have never heard of one who had a transmission problem as a result.
I know of many who have had to rebuild Kanzaki gear boxes but don't know the causes in each case.


My main concern with a freewheeling prop while sailing is unnecessary wear on the entire drive train.
If the gear box is splash lubed then it is fine to let it spin and Yanmar stands behind this.

Cutlass bearings I have seen go 6000 engine hours before needing replacement and as much as 40,000 nm boat travel distance.. Alignment issues are usually the culprit in cutlass wear as they do not allow a water/film layer between the shaft and rubber.

While Yanmar may recommend leaving the transmission in neutral when sailing,

(1) I would like to read or hear their views of the additional wear this causes, and
I have spoken with them at length about this and also seen the cones of a gear box that needed re-building due to locking the gear. The guys who report they can't get it "back into neutral" "without starting the engine" are specifically why this MSA was created.

If it locks up you should never "force" it back to neutral and should always start the motor in reverse then switch to neutral. Yanmar does not make these MSA's on a whim. Reverse is used so limited that wearing out the cone is rare from locking but the prop does not simply load up the cone and always bury it into the reverse gear especially at low sailing speeds. It can cause the cone to chatter in the gear which can cause undue wear.

The cone is an aluminum bronze alloy and the reverse gear is iron. The cone gives not the reverse gear. After a while of this loaded chattering the cone can wear to a point where you may have problems. When you put it in reverse the motor can tend to feel like it is "hopping" because the cone is slipping until it has been driven deep enough into the gear to lock up and stop slipping. This MSA is more about the problems surrounding the ability to not get it out of gear than anything and the resulting damage that can ensue if trying to force it back into neutral.

(2) I'd like to read or hear what the makers of the transmission have to say about this issue as Yanmar doesn't make transmission, I believe.
Unless you have the rare Yanmar that has a Huth/ZF box, which you can lock in reverse, or a hydraulic Kanzaki box which must have an external shaft locking device, then the Kanzaki box is a Yanmar product and they are the manufacturer.

Finally, if any one out there has a credible story about how his/her transmission was specifically damaged by locking it in reverse while sailing, I would hope they would post it here.
This was a cone clutch from a full keel boat. They had a fixed two blade they locked in reverse. The motor began bouncing violently when put in reverse as the cone was apparently slipping and not fully engaging. The cone was worn according to the re-builder on the reverse side of the cone. They usually see the forward side worn. Motor had 1400 hours.

 
Jun 4, 2004
1,071
Hunter 410 Punta Gorda
Thanks Maine Sail for the information. As usual you are a wealth of information and we are all the better for it. I just ordered my folding prop so hopefullly this will reduce the spinning while in neutural.
 
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