I believe my 1978 vessel has the original QM15 and is still running fine. There are two zincs that need to be replaced regularly. My engine doesn't have an hour meter so I have no idea how many hours may be on it.
08-03-2010 06:32 PM
RWC in an old boat can be a big issue. It really depends on how it was taken care of. like if the inlet water was shut off when the engine was not in use, prevents a rust line in the engine where the water level equalizes with the ocean. An engine will really rust if it has air above salt water inside the engine. One easy test would be to warm the engine up and use a non-contact thermometer to measure all over it looking for hot spots. It is possible to identify plugged passages by looking for hot spots on the engine.
A lot can also be learned from the color of the exhaust and the sound. An oil sample can be sent away for analysis too.
A lot of us have had old engines, they take more maintenance to keep going. It would be worth it to have an engine survey done. The cost is easily justified on an old RWC engine and if you buy the boat you will gain valuable knowledge from the surveyor. Make sure the you find a mechanic that knows this particular engine well to do the survey. They will know what to look for.
08-03-2010 01:51 PM
If the engine was 'run hard', reasonably maintained, etc. such QM engines 'can' easily reach 8000 to 10000 operating hours.
What typically destroys most marine engines is 'rust', from the 'inside'; the outside was designed for contact with the 'marine environment' and usually includes a hefty amount of 'corrosion allowance'.
08-03-2010 01:43 PM
Yanmar 2QM15 - how long will they live?
I'm buying my first sailboat, and it has a 30 year old Yanmar 2QM15 RWC diesel.
The boat looks pretty clean and pretty well maintained. It's hard to say for sure, but I get a good feel about the boat itself.
I do have some concerns about the engine though, largely because my whole life has been spent on shore; salt water is a thing to keep away from motors, not a thing to pump through the middle of them!
The overall visual appearance of the engine looks like what I would expect a 30 year old marine engine to look like. There's a bit of foamy corrosion around a couple of fittings and a wee bit of surface rust here and there. There has clearly been no attempt to clean it up to hide anything.
Overall it looks .. 30 years old.
My problem is that if this does bite the dust, I'm looking at paying more for a new engine than I paid for the whole boat, to say nothing of the initial problem of trying to SAIL into my slip!
So, what's a reasonable life expectancy for a 2QM15?
And is there anything obvious I should look for before going to the expense of a proper mechanical inspection?