Slowly Sinking

26ft_bathtub

26ft_bathtub

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3 Aug 2006
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343
Location
Chesapeake Bay
www.picaroonblog.com
My boat takes on water unless the raw cooling water intake is shut.

(Yanmar refers to this as the 'Kingston Cock', but I'm not sure if that term is used widely, and I definitely recommend not Googling it unless you're really into Jamaicans.)

Now, I know from the manual that the grill for the intake is on backwards, but while I could see that affecting the intake of water, I doubt it would cause a leak. There is no problem when the engine is running.

We're talking about a pretty small amount of water here, so I'm in no danger of sinking (sorry, the subject line was a disappointing lie to draw you in), but my bilge is about ¼ inch deep, so it doesn't take a lot to get wet feet.

Any ideas?
 
Have a good look around the seacock and the pipework up to the raw water inlet on the pump.When the motors running the pump will reduce the pressure on the suction side which may account for why it doesnt leak with the motor running.

try drying everything then open the Sea cock and wipe around with coloured absorbent paper that shows up any wet bits. good luck little leaks can be a swine to detect.
 
Dry everything thoroughly and sprinkle talcum powder around. Watch carefully.

Alternatively close the seacock when the engine is not in use.
 
No surprise to see that the Manky Wee Boat sailors are up to speed with leak detection and avoidance techniques. /forums/images/graemlins/cool.gif
 
Sorry. I've obviously misunderstood. I thought that "We're talking about a pretty small amount of water here" meant that we were looking for a small amount of water. /forums/images/graemlins/smile.gif
 
Could have to change the name now to "manky wee boats international" /forums/images/graemlins/cool.gif
 
The Kingston cock that yanmar refers to is the term for the drain plug on the lowest point of the cooling system. If you mean that is where it is leaking then it's only the water in the cooling system that is running out out through the leak. If this is the case replace the kingston cock with bolt and fibre washer to seal the hole.
 
What you mean when you say "no problem with the engine running" is that you can't see an obvious leak that gets worse with it running surely? As this is not an obvious leak anyway how would you know? You have no evidence to suggest it stops when the engine is running have you?
Check all your exhaust joints too...
Also the pressure does not reduce appreciably in the inlet pipe with the engine running unless the pipe size is very small and a hole here would still leak with engine running. If you don't believe me try slackening off the pipe joint so it leaks obviously and see if starting the engine stops it. It won't. If shutting the inlet cock stops the leak it suggests the leak is on the inlet side but not necessarily. The main culprit for a small leak like this is often the water pump bearing seal. As others have said, with everything dry put some toilet paper under the offending part and see if it gets wet.
 
I have a YSM8, but fortunately a very deep bilge in comparison to yours. My bilge is 4 inches at its deepest. I had similar problem last year. The water leak was in the raw water pump. I have spent many hours replacing seals, bearings and even the water pump drive shaft. My water pump still leaks about the same amount as it did before I tried to fix it. Perhaps the major difference with mine, is it leaks more with the engine working as it is then pumped out. My final decision - live with it and every so often I pump out the bilge using a hand pump. Close the inlet valve and the leak stops.
Otherwise the website and phone assistance at Aqua Marine in Chertsey is very good. They definitely can find any part you are looking for, even though sometimes it can take a little time.
 
[ QUOTE ]
The Kingston cock that yanmar refers to is the term for the drain plug on the lowest point of the cooling system. If you mean that is where it is leaking then it's only the water in the cooling system that is running out out through the leak. If this is the case replace the kingston cock with bolt and fibre washer to seal the hole.

[/ QUOTE ]

Not so, a "kingston cock" is a bronze skin fitting with integral valve and vertical filter, you will find them mostly on boats which have or had a stuart turner engine. /forums/images/graemlins/smile.gif
 
Not so sure about being linked to Stuart Turner.

Also not sure it is specifically a filtered valve.

Certainly believe that a Kingston Cock is the water inlet valve on the skin fitting though.
 
Oh Gawd! Why do I do this???
A KINGSTON valve is a valve manufactured by the Kingston valve company. Its like calling a vacuum cleaner a Hoover and the term is miss-used in the same way. At one time kingston did make a seacock for submarines and that is why everybody thinks of them as a seacock.
Traditionally Kingston were famous for pressure relief valves and yes, some old Stuart Turners did utilise a seacock with a one way valve in them manufactured by Kingston to stop the water inlet pump from losing its prime when the engine was switched off. If you REALLY want to look on their website it's easy enough to find www. kingstonvalves.com. Yawn.....boring.......
 
Sounds fascinating. Glad that filled a knowledge hole.

So it is a bit like sailboards and Windsurfers.

If you put in Kingston Cock in a.s.a.p. website it come up with all their inlet valves. Presume like Hoovers and Windsurfers it has become more of a generic term.

Putting it in Yahoo....well you can imagine where this might lead!
 
(Yanmar refers to this as the 'Kingston Cock', but I'm not sure if that term is used widely, and I definitely recommend not Googling it unless you're really into Jamaicans.)

That unfortunately is the biggest trouble with GOOGLE, the world and its friend (fiend) uses it for ALT/SEX.

If you use www.IXQUICK.COM which is used and devised by engineers /forums/images/graemlins/grin.gif then you will get a far better result.

NB; This search engine accepts Boolean Logic and if you have a group of words, you have to surround the complete phrase with double inverted commas [Shift 2 in the UK]. "Kingston Cock"

There are otther more subtle tricks like only searching web-sites ending DOT co DOT uk.

To do this, type in the search phrase and then, leaving a space, type URL:co.uk after it. This doesn't work on Google which is designed for plebs.

"Kingston Cock" URL:co.uk

I hope this helps you and others?

regards Dave W [watching a rising glass 1020mbars ]
 
[ QUOTE ]
You have no evidence to suggest it stops when the engine is running have you?

[/ QUOTE ]

Yes.

If I start out with a dry bilge, then steam for a while (with the cock open, obviously), there is no appreciable water accumulation in the bilge. If I sail with the cock open, there is.
 
You may all be right, but I'm really quite sure that my Yanmar manual is talking about the raw water intake valve.

Anyway, it's moot.

The common thread of advice seems to be 'find the leak using paper or talc, then deal with it or ignore it and just close the cock when it's not in use.

Incidentally, Glayva, mine is also a YSM8: 26 years without a rebuild and still runs like a charm. Little troopers aren't they?

Thanks for the discussion, everybody.
 
Interesting. In that case, when sailing, could the exhaust be taking in water when on one tack or another I wonder? Is it very near the waterline? Could it possibly go under when sailing?
If the skin fitting is OK and the hose firmly screwed on with a jubilee clip and the hose goes up in a swan neck as it should inside the boat to stop water ingress, you shouldn't have a leak there... worth checking though.....
 
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