Question on Yanmar 3YM39 engines

[Jaylaw]

Hi I’m interested in a catamaran that has 3000 hours on both engines. The engines have been professionally maintained. Can I have some advice please. Is that a lot of hours and what sort of life expectancy would you expect with good maintenance etc of the Yanmar.

The boat I’m looking at is in excellent condition 10 years old, the only thing is the engines hours are a bit higher than I was interested in. That maybe irrelevant if for example 3000 hours is mid life for that type of engine.

Thanks for your help in advance.

[slug]

Originally Posted by Jaylaw

Hi I’m interested in a catamaran that has 3000 hours on both engines. The engines have been professionally maintained. Can I have some advice please. Is that a lot of hours and what sort of life expectancy would you expect with good maintenance etc of the Yanmar.

The boat I’m looking at is in excellent condition 10 years old, the only thing is the engines hours are a bit higher than I was interested in. That maybe irrelevant if for example 3000 hours is mid life for that type of engine.

Thanks for your help in advance.

Don’t know

Generally at you engine hours a complete service is required

Injector pump ,injectors , fuel pump , all rotational equipment like pump bearings seals alternators , exhaust , flexible hoses ....
You should ask a Yanmar engineer for this service protocol and an estimate

It won’t be cheap

Use this knowledge to downgrade the asking price

[Jaylaw]

Hi Thanks for your time in replying to my post. Very helpful.
Regards

[Bycrick]

The accumulated hours aren’t usually any indication of the state of the engine. My yacht club bought a used Yanmar 3GM engine for one of the club launches. No idea of how many hours were on it. Supposed to have been sunk. It was put into a boat and used for a lot more hours before it was sunk (maybe again). It then sat for 6 months before somebody looked at it. We did a minor overhaul, fixing the stuff that was obviously bad, but weren’t going to invest much. The last time I looked at an hour meter, which we installed with the motor, it had 8k+ hours more. That was two years ago and it’s still running.

[Tin Tin]

- Those engines, if properly maintained per the manual could last 8 - 10k hours. Ask the owner for the receipts for all the services, down load the service manual from Yanmar and check that the services covered ALL the elements that specified to be done. Things that usually are not done on the scheduled time by DIY servicers are the replacement of all rubber hoses, the valve back lash adjustments, exhaust elbows etc. If you look in the service tables you will note often the comments is "At x number of hours OR by x number of months or years which ever comes first." You say it has been professionally serviced, so all these items should have been done and signed off by a professional mechanic over the life of the engine and hopefully the service manual has been filled in too. Applies to sail drives too.

[skipperpete]

I think Yanmar would be astonished if you told them that the useful life of of their engines was only 3,000 hours. Tin Tin and Bycrick both make very useful comments on this issue and I suggest a reasonable life before intervention would be in the vicinity of 6 to 7,000hrs IF well maintained and not exposed to the trauma of a flooded exhaust or a major overheat.
Pete.