Yanmar Saildrive Raw Water Intake Valve Solution?

circa1971la

circa1971la

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Nov 23, 2018
32
Schock Harbor 25 Los Angeles
Hi I have a Yanmar 2YM15 diesel with an SD20 saildrive.

I have had to replace the raw water shut-off valve twice now as it stays stuck in the open position. Each time it is very expensive to haul out the boat and do this for such a small part. I have been told that this should be replaced with a ball-valve type of unit but Yanmar does not make one and still have to haul it out to change this.

In the meantime, I read that I could install and install-line valve between the saildrive and the water pump. It seems if I had the clamps, valve and a plug, I could cut the hose and quickly plug it then do the valve one side at a time without much water intrusion. I really appreciate any thoughts or experience with this. Am I crazy? Also, even if the shutoff worked, this seems like a nice back up to have on board.

Thank you all so much. Please leave out the sarcasm I really appreciate the knowledge out there. Here’s a simple diagram attached
 

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Rick Webb

Rick Webb

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Jun 2, 2004
3,644
Hunter 23.5 Fort Walton Yacht Club, Florida
I do not see the advantage.

The most suspectable failure point is the hose and you are spending a lot of time and effort to protect a little less hose.

If it is to protect other components from leaking the valve and clamps are not too expensive and it will allow you to sleep at night, then I'd say it was probably worthwhile.
 
circa1971la

circa1971la

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Nov 23, 2018
32
Schock Harbor 25 Los Angeles
The main issue is that I’m having to crank my engine a lot and bleed it after it’s been sitting for a while and I know I need to shut off the raw water intake when doing so to prevent water coming into the motor. So the main motivation is to be able to shut this off not because I’m concerned about our leaks or seeing any.
 
Davidasailor26

Davidasailor26

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May 17, 2004
6,113
Beneteau Oceanis 37 Havre de Grace
circa1971la said:
The main issue is that I’m having to crank my engine a lot and bleed it after it’s been sitting for a while and I know I need to shut off the raw water intake when doing so to prevent water coming into the motor. So the main motivation is to be able to shut this off not because I’m concerned about our leaks or seeing any.
Click to expand
I wonder what the root cause of that is. My YM series starts in less than a second, even on cool mornings. When I change the fuel filters I bleed it by hand it it is harder to start, but still not enough to need to close the seacock.

Having said that, it is still best practice to close thru hull valves when leaving the boat anyway.
 
Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
7,581
Hunter 310 West Vancouver, B.C.
Hi @circa1971la . I don't have a saildrive for propulsion but I do find your situation to be most interesting. And then there's the $500.00 +/- for the haul out to replace a nickel and dime valve. Most painful.

My apologies but I've got to say I find your attached pic to be confusing as hell. Could you please add any info you can to my questions :

1774215896083.png



circa1971la said:
I could cut the hose and quickly plug it then do the valve one side at a time without much water intrusion.
Click to expand
You don't want to trust your gut in a case like this. Calculate the depth of this stuck valve below the water line of your boat.

1774216223315.png


No gut feelings here. Exact number of inches. And, what is the diameter of the existing valve ?

Next step, post a close up hi res picture (several is much better) of the stuck valve as far as position and ease of getting to the valve. Get close enough so that we can see how you installed it last time. What thread sealant did you use ? Give us everything you can ............ we're not there.

circa1971la said:
I have been told that this should be replaced with a ball-valve type of unit but Yanmar does not make one and still have to haul it out to change this.
Click to expand
Yanmar doesn't make valves so they can't help you. If this valve can be safely removed in the water (above paragraph will tell), you should be able to install a good quality bronze valve for ~$30.00 depending on size. Any chance you've got the old stuck valve kicking around ?

What material is the new bronze valve screwing into ?

Educate me as to why the Yanamar raw water pump feeds water to the sail drive. Interesting.
 
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circa1971la

circa1971la

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Nov 23, 2018
32
Schock Harbor 25 Los Angeles
I’m sorry Ralph the photo is from AI... the point was just to show the inline valve. Anyone with a Saildrive out there will understand this issue and frustration with these. The seawater comes through the Saildrive into a line that connects to the engine. The raw water pump uses this to cool the engine. The valve is brass (photos attached) and they are notoriously crappy and get seized. The valve is accessed in the engine starboard side. Fortunately it’s seized in the open position but there are times when you want to shut this off. Nothing is leaking inside. Because of immense pressure underwater, you cannot change this in the boat slip with a diver. You have to haul it out to replace it. So my idea about simply putting an inline valve was to be able to do this while the boat still in the slip. The photo of the valve installed is from another boat I found online but is basically the same setup.
 

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JoeWhite

JoeWhite

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Mar 6, 2008
1,490
Catalina 1999 C36 MKII #1787 Coyote Point Marina, CA.
It seems that you can install a ball valve that is screwed into the sail drive and is made of bronze. Since you have replaced it before you know the type of thread that it has. It is probably tapered.
What is the size of the opening ? You should be able to replace it in the water. Enclose the sail drive in a 55 gallon contractor garbadge bag to reduce water ingress.
 
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Project_Mayhem

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Sep 24, 2018
4,450
Catalina 30 MKIII Chicago
The valve looks like it can be disassembled for service. Try loosening the top of it to see if you can turn the handle.

If servicing it in water, you can also have a trash pump or similar on standby. They don't cost much to rent for a few hours or a day
 
C

colemj

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Jul 13, 2004
1,039
Dolphin Catamaran Dolphin 460 Mystic, CT
Source the valve from Volvo. They use the same thread and Volvo's are ball valves.

People complain about Volvo a lot, but when it comes to saildrives, Yanmar cheaps out everywhere. Both drives are made by ZF, and are essentially identical, except Volvo specs higher quality components like the ball valve, hardened prop shafts instead of plated steel, roller thrust bearings instead a copper washer, and the list goes on. You just don't see the huge amounts of issues the Yanmar saildrive threads have in Volvo saildrives.

Mark
 
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dlochner

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Jan 11, 2014
13,954
Sabre 362 113 Fair Haven, NY
If you do this job in the water, what's your Plan B if the bag fails or something else goes wrong and the job can't be completed quickly?
 
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colemj

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Jul 13, 2004
1,039
Dolphin Catamaran Dolphin 460 Mystic, CT
Doesn't your raw water intake go through a strainer between the drive and the engine? If not, it should. And that strainer is usually placed above the waterline for convenient cleaning without water ingress.

If you do have this, then just add a valve there if you want one. This will still leave the risk of a split hose or other issue between the saildrive valve and the new valve.

Mark
 
Vincent Williams

Vincent Williams

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Jul 18, 2020
19
Catalina 275 11 Westbrook, CT
new issue
275 # 11 Yanmar diesel and sail drive
just had water intrusion alarm go off on the sail drive. Has anyone had this happened before? boat was in fresh water until 2023. There was a small amount of water in the bilge below the diesel. Got the boat in, opened hatch dried out compartment but I still have alarm. Had new seal placed at hull a few years ago. I understand this is a sensor higher up at motor sail drive junction.
 
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colemj

.
Jul 13, 2004
1,039
Dolphin Catamaran Dolphin 460 Mystic, CT
Vincent Williams said:
new issue
275 # 11 Yanmar diesel and sail drive
just had water intrusion alarm go off on the sail drive. Has anyone had this happened before? boat was in fresh water until 2023. There was a small amount of water in the bilge below the diesel. Got the boat in, opened hatch dried out compartment but I still have alarm. Had new seal placed at hull a few years ago. I understand this is a sensor higher up at motor sail drive junction.
Click to expand
The Yanmar saildrive uses a double boot seal to the hull. The first boot seal does all the work, and the second one is just a thin piece of rubber with a water sensor sitting between the two. It only takes a bit of condensation or water from inside the boat to get between the seals and trigger the alarm. Once the sensor is damp, it is difficult to dry it to the point the alarm stops. This is a very common annoyance with Yanmar saildrives.

Pull the water sensor out and dry it. Look between the upper seal and the lower seal to see if you have a lot of water. If so, suck it out and wait to see if it returns. If it doesn't, then there is no leak problem to be concerned about.

BTW, this sensor is down at the base of the drive where the rubber boot is. Not up where the motor joins the saildrive. I'm not aware of any water sensor on Yanmars that determine water in the internal oil.

Mark
 
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