Engine Hours

[Flyingriki]

Reading the thread of the fellow burning oil there was a comment that at 3000 hours a Yanmar should still be running well. I'm looking at boats and see two 1995 models, one with 585 ours and the other with 3500.
Wondering what is a life expectancy for a 50+ hp Yanmar and I know it probably depends on how well it was maintained. Just wondering about experiences.
Thank you!

[Calif.Ted]

I asked that question once of a guy that used 3GM30 engines in a shoreboat operation, he replied "I don't know, we just replace them every 10,000 hrs."
That's a lot less then 10 years however so "It all depends" those engines ran at operating temp at least several hours a day which is probably better than sitting for months at a time.

[hellosailor]

Rule of thumb for small marine diesels (i.e. sailboats) is 5-10,000 hours between overhauls IF the engine is properly maintained. How big is a thumb?

You can ruin one way faster if you never change the oil and just run it at idle speed to coke it up. Or you can get the full 10,000 if you keep it under proper loads, proper cooling, proper oil changes.

Like a used car: A 200-mile highway run every day can be less wear than four local 2-mile trips to the convenience store. Really.

So you look at overall condition, see if the engine space seems clean and well maintained, send out an oil sample for analysis, run it under load and let it heat up and see if anything seems noteworthy. Check the belts, check the hoses, see if they look like they've been serviced on schedule too.

If you're down to purchase time, an engine survey by a real mechanic can be worthwhile too, sometimes.

[Hunter33]

I have a 20qm with regular maintenance runs perfect it is 40yrs old now

[Rhapsody-NS27]

Originally Posted by Flyingriki

I know it probably depends on how well it was maintained. Just wondering about experiences.
Thank you!

Yes, you're right. "it depends" is a good answer.

The engine on my boat wasn't really taken care of and while it had about 730hrs, it wasn't long until it was dead. Last year, I pulled it from the boat and did a partial rebuild. Only after I started taking parts off of it did I realize just how bad it was.

[Hunter33]

Preventive maintenance is key when you only have one engine unlike larger boats when they have dual engines normally you can limp home on one kind of like an airplane with a single prop or a dual prop

[Flyingriki]

Thank you all!
will get a good survey either way. Kind of surprised to such a variation between 2 22 yr. old boats. Figure 3300 hrs. is probably one used regularly and the maintenance will be crucial. The 500 hr. must either be overhauled or sat a lot and suspect.
Thanks again.

[rognvald]

Engine hours tell you nothing about an engine's maintenance. And, just like in automobiles, some dishonest people change the meter/hours. So, if I were ever going to buy another boat--- after I did MY initial inspection, I would hire a certified marine mechanic, at my expense, to pull the head and check the pistons, cylinders and valves. If the engine is bad, you can re-negotiate or walk away. If it is good, there is no guesswork. A couple hundred dollars could save you countless sleepless nights and thousands in mechanical repair and would do no harm to the boat or its owner. Perhaps this sounds a bit neurotic to some, but it's your money. There's always another boat. Hope this helps.