High engine hours due to watermaker - a problem?

mobeydick

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A call upon the assembled wisdom!

I am looking at used sailing boats (again) I have seen a couple with higher-than-average engine hours for the year: e.g. 1,580 hrs on a 2005 boat, 1650hrs for a 2008 boat.

This is due (I am told) to the use of the watermaker. I would say this would mean many hours under light load.

How much of a problem (if any) could this be? i.e. should I be negotiating a substantial price reduction, or walking away, or just be happy it has a W/M?

Thanks for any opinions!!

MD
 

FlyingGoose

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A call upon the assembled wisdom!

I am looking at used sailing boats (again) I have seen a couple with higher-than-average engine hours for the year: e.g. 1,580 hrs on a 2005 boat, 1650hrs for a 2008 boat.

This is due (I am told) to the use of the watermaker. I would say this would mean many hours under light load.

How much of a problem (if any) could this be? i.e. should I be negotiating a substantial price reduction, or walking away, or just be happy it has a W/M?

Thanks for any opinions!!

MD

Really do not think there is any issues , a marine diesel will go on for a good many hours ,if been well maintained and serviced, my poor engine has 5600 hours and still starts first time :D
 

jdc

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...1,580 hrs on a 2005 boat, 1650hrs for a 2008 boat....

But that's nothing! My 2005 boat has done more than 2500 hours and the engine is just getting nicely run-in. A modern diesel will do around 10,000 hours before needing anything major done, and probably in excess of 20,000 hours before one could consider it getting old. As a check, compare to trucks: a million km is normal enough. 1 million / 80 kph average say = 12,500 hours., and boat engines usually get an easier life. As for tractors, I have tractors around 40 years - one 60 years old - which just run and run. Say 20 hours a week, so 1000 hours a year, so 60,000 hours! Sure it drips oil a bit, but Fordson Dexters always did and there's life in the old dog yet.
 

mobeydick

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Thanks for replies.
Granted these engines run for a good many hours ok under load, but (I understand) the very light load of a W/M could be a problem due to bore glazing?
 

prv

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Thanks for replies.
Granted these engines run for a good many hours ok under load, but (I understand) the very light load of a W/M could be a problem due to bore glazing?

I don't know enough about engines to comment authoritatively, but I agree the replies so far don't seem to have considered the load or lack thereof. I'd agree that the hours wouldn't be a concern if they'd been run under load for propulsion, but that's not what you asked.

Pete
 

RichardS

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I don't know enough about engines to comment authoritatively, but I agree the replies so far don't seem to have considered the load or lack thereof. I'd agree that the hours wouldn't be a concern if they'd been run under load for propulsion, but that's not what you asked.

Pete

The problem, although it's only a relative problem, is caused by starting and stopping before the engine is ever warmed up. Generators and HGV's do not normally do this even though they might run at idling speeds, or close to it, for hours on end. Assuming that running a watermaker does not require stop/start and the oil quality is maintained, there will be no problem with this application as in #3. :)

Richard
 

duncan99210

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Our engine has in ecxcess of 4500 hours on it (on a 19 year old boat) probably about 30% of that at a fast idle for battery charging. The engine exhibits no sign of bore glazing, starts first time and burns no oil to speak of. So, unless the engine you’re looking at is hard to start (loss of compression) or burns lots of oil, I reckon it’s not likely to be a problem.
 

Ruffles

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I'd be far more concerned with low engine hours. I feel very guilty starting our little diesel when it's been sitting neglected for 6 months. Unfortunately it always starts instantly which can't do it any good. I usually pull the stop handle and turn it over for 5 to 10 seconds. No idea if it helps though.
I'm guilty of running ours at idle. But then idle is actually 50% of the speed we motor at!
 

sailaboutvic

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A call upon the assembled wisdom!

I am looking at used sailing boats (again) I have seen a couple with higher-than-average engine hours for the year: e.g. 1,580 hrs on a 2005 boat, 1650hrs for a 2008 boat.

This is due (I am told) to the use of the watermaker. I would say this would mean many hours under light load.

How much of a problem (if any) could this be? i.e. should I be negotiating a substantial price reduction, or walking away, or just be happy it has a W/M?

Thanks for any opinions!!

MD

If your looking for a reason to reduce the price , you be better off looking for a genuine one ,
if the boat is of real interest to you be careful you don't piss the owner off , any help or info you may need after you buy the boat may not be for coming .
 

Graham376

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Our engine with unknown history (boat fairly new to us then) blew all the oil out because of stuck rings in one cylinder. On phoning Diamond Diesels (Mitsubishi importers) for parts, their first comment was "must have spent a lot of hours at low off-load revs". Bores were well glazed and rings gummed up with unburned fuel.
 

Graham376

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The issue isn't so much revs as load and it's effect on cylinder temperature and pressure.

In Diamond's opinion (and they're experts) off load includes motor sailing at low revs because the engine isn't working hard. They suggest engines need to be periodically run at maximum revs under load, to clear them out. Many boat engines were designed for small plant, running hydraulic pumps at constant fairly high revs but, the load varies as the machine works whereas the load from a prop when motor sailing remains almost constantly low.
 

FlyingGoose

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To OP your question is only truly going to be answered if you get an Engineer in to survey the Engine and give you his recommendations, but to ask for a reduction (hefty one in your words) without knowing if there is a problem will get you know were.There is no way of knowing the amount of idle hours and running at temp hours for this engine.
So if you are worried , pay for a good inspection, but expect the owner to be non compliant for your reduction in money unless their is a problem found:encouragement:
 

mobeydick

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Thanks for all replies.
I would of course only be seaking a reduction if high hours on a W/M were known to be a possible problem.
 

Dockhead

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Thanks for all replies.
I would of course only be seaking a reduction if high hours on a W/M were known to be a possible problem.

As others have said, I wouldn't necessarily consider that high hours at all, if the boats have actually been anywhere. I have 3300 on my 2001 boat, 2500 of which have been put on since 2009, so 250 hours a year. None for battery charging or watermaker use, since I have a separate heavy duty generator.

I would do the normal engine checks -- make sure it doesn't smoke, burn oil, or show signs of low compression or low oil pressure or overheating, or ever having been run out of oil or overheated. If all that checks out, I wouldn't worry about it. The hours reflect a normal amount of propulsion for a boat which has been used at least a few months every year.
 
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