Yanmar 10GM

[Jeep]

Hi all, I have a seawater cooled Yanmar 10GM and it has a habit of setting off the 'water' alarm. It seems to dislike turbulent water but it will also happily run for an 1 1/2 quite happily and then go off for no apparent reason. I have checked the impeller and the seacock filter and there is always water coming out the back when the alarm goes off. I put it into neutral and after 30 secs or so the alarm goes off and I carry on for maybe another half hour or so and the same thing happens again. Its about 50 hours 'old' and probably needs a service but can anyone help with this specific problem . . . . ?

Thanks in advance.

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[NigeCh]

If the engine is only 50 running hours old then you've either got not enough water coming through (Crippled intake pipe?), a faulty thermostat, or a blockage/constriction before/after the impellor.

Take it back to the installer and get them to sort it out.

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[bugs]

maybe the belt is slipping and reducing the amount of water needed.

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[pete]

Hi Jeep
I also have a 1GM10 and although I like the engine this is I think a weakness,
Occasionaly my engine has refused to prime on starting or more rarely has perhaps sucked in airated water when motor sailing.
I have had the boat around 4 years and find some impellors are better than others although I like the idea of the Globe run dry impellors and have used them succesfully in other engines they dont seem to like my Yanmar.
Now I carry several OEM impellors but when I find one that is working well I dont change it anually as I have found my probs usually start after a impellor change.
Just a point though are you sure you do not have a faulty temp sender you could easily check it with a multimeter and a pan of hot water (I think the raw water senders switch around 55 to 60 degrees)
I bought a fresh water one recently and it cost £49
and dont be tempted to carry on unless you are sure its a faulty sender as I burnt out the exhaust hose after about 3 mins( it totally delaminated )inside

Pete


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[NigeCh]

It\'s direct drive (nm)

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[dickh]

Re: Yanmar 10GM/Impellor Problem?

I seem to remember that Yanmar had a problem with their impellors in the past in that the rubber vanes became unbonded from the central bush, causing the cental bush to spin but not drive the vanes - thus causing low water flow. Could this be your problem? Might be worth checking that the rubber is still bonded to the centre....


<hr width=100% size=1>dickh
I'd rather be sailing... /forums/images/icons/smile.gif

 

[Jeep]

Re: Yanmar 10GM/Impellor Problem?

Thanks for the info all, I shall check all the points out next time I'm on the boat. Going back to the original supplier isn't really an option though; its only 50 hours old but also several years if you get my drift!

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[Seapepper]

there was a thread on this a while ago and I seem to remember that it was due to a faulty connection somewhere behind the Yanmar control panel.
John

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[snowleopard]

yes, i also have this problem (with a raw water cooled 3GM30). in the past it would suddenly overheat while under way in choppy conditions but lately it won't deliver any water unless i manually prime the pump but once started it runs ok.

i've been thinking about a new pump body but maybe i should try different impellors. the engine has about 1500 hours on the clock.

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