Yanmar Engine Life Expectancy?

[TacomaSailor]

When we bought our new boat with a new Yanmar 4JH2E I hired a mechanic from the local Yanmar dealer who dealt primarily with commercial fishing boats.

He told me that the commercial Yanmars would easily run 10,000 hours because the commercial owners put them at 70% - 80% power and ran them like that for days at a time (it is a LONG way from Tacoma WA to SE Alaska). They kept them hot and revving.

He said they had serviced lots of glazed and failed Yanmars in sailboats - all failed because, as dozens others have said, Yanmar is a high RPM engine. He said it is mandatory to run at 3000 RPM (the 4JH2E) for five minutes every 5 hours or more often. He also said it is critical to run the engine at 3000 RPM for 10 seconds after docking - then let is slow to idle for a couple seconds and shut it off.

And... if you start the engine - get it all the way up to FULL operating temperatures before shutting it down. Not reaching full temp (190 F) will not "cook" the acids and water out of the oil and will lead to early internal corrosion.

He told us to set our Maxprop so we could comfortably run the engine at 2600 - 2750 RPM forever. Our Max RPM is 3200 for an hour and 3400 for five minutes (I think) and he wanted the engine to consistently run in the 70% (~2400) to 85% (2850) range under normal cruising.

And - he said the worst thing a Yanmar owner can do is charge a 12V battery bank with a 135 amp alternator - it puts less than 3 HP load on the engine and will quickly glaze it - thus our huge solar array.

We've followed his advice and have 2850 great hours on the engine.

PS - while testing the injectors at the dock, in neutral, he had the engine running above 4000 RPM - don't know how far 'cause the tack stops at 4000. I picked up my feet to avoid the flying pistons and rods but he assured me no Yanmar has ever blown due to high RPM.

[Bash]

Every Yanmar mechanic I've ever used has given the same advice: run the engine at least 80% of WOT. I have the 75 hp turbo currently, and take it up to at least 2,800 RPM if I'm going to be running it more than ten minutes. And every few hours I'll run it at 3,200 RPM just to make it happy, although at that point I'm using fuel inefficiently because I'll be doing hull speed.

[Harter]

Hi I would like to add just a bit about Diesel motors I have had as light plants in the oilfield, One motor Perkins Diesel I had ran 27000 hours before needing a rebuild.
And the water pump had given up at that time, We were doing oil sampling on this motor to see just how long it could go, The motor ran 24 hours a day with only shut downs to do oil changes, at 250 to 400 hours in between changes,
I am still on the hard and shopping But I would like to thing Sail boat motors have a lot more life in them then 2000 hours.
Terry

[alexvk2zal]

I have a 2002 3JH3E on Catalina C380 light use for nearly 18 years -less than 1000 hours- apart from regular service I have only had to replace the exhaust elbow -- starts instantly and doesnt burn any oil whatsoever -I keep it very clean and Lanox on all exposed ferrous bits,the PSS shaft seal does not leak so there is not such a corrosive engine compartment -looks good goes good-- am still amazed that there is no anode in the heat exchanger. Whats not to like?

PS I had a bimini built around solar panels so I don't use the Yanmar for battery charging - on a swing mooring - no shore power ever.

[kev_rm]

You heard it here first, folks - Hone your engine without taking out the pistons.

LOL

Originally Posted by djmarchand

= If this doesn't work, the only sure remedy is to pull the head and pistons and run a hone down the cylinders.

David

[Renegde_Sailor]

It sounds to me like he screwed up somewhere, a new engine can still have problems, you don't just set it and forget it.

[GILow]

Originally Posted by kev_rm

You heard it here first, folks - Hone your engine without taking out the pistons.



LOL

I think you might want to read that again.

[Uncle Bob]

Originally Posted by GILow

I think you might want to read that again.

Nah, literacy and comprehension are sooo overrated.

[Q Xopa]

Originally Posted by kev_rm

You heard it here first, folks - Hone your engine without taking out the pistons.

LOL

I assume "pulling the head and pistons" would be referring to taking the pistons out?

[GILow]

Originally Posted by Uncle Bob

Nah, literacy and comprehension are sooo overrated.

Like, I know right?!

[RaymondR]

The cure when they ran water pumps off the tractor power takeoff for long periods and it wouldn't pull the plow was Omo into the intake manifold.

[mvweebles]

A friend who trains factory mechanics for John Deere Marine Propulsion and Northern Lights tells me there are two keys to long diesel life:

1. Fix all leaks immediately no matter how tiny.

2. Run them like they're stolen

In short, he says Diesels don't die natural deaths. You have to kill them. Not following those two rules is a fast path to assassination.

[GILow]

Originally Posted by RaymondR

The cure when they ran water pumps off the tractor power takeoff for long periods and it wouldn't pull the plow was Omo into the intake manifold.

Do you get bubbles out the exhaust?

[skipperpete]

Originally Posted by RaymondR

The cure when they ran water pumps off the tractor power takeoff for long periods and it wouldn't pull the plow was Omo into the intake manifold.

Caterpillar at one time had a deglazing procedure involving a fine abrasive powder that was introduced directly into the intake manifold at hi idle one cylinder at a time, a very aggressive method of instant deglaze. The powder was similar to a household cleaning powder called "Bon Ami" in Australia.

[Group9]

I think Yanmar is probably right here. It really is almost impossible to run these engines too hard (as long as it is propped right). On the other hand, it is easy to screw one up by running it light, consistently, or not at all. Our last 4JH-BE had 6700 hours on it when we sold it and it still had the power it had when we bought it with 1300 hours on it. We didn’t baby it and ran it near full throttle a lot of the time.

I agree charter service is probably the best environment these engines can live in. Try and emulate those conditions. When we run our Yanmars at the dock, we don’t idle them except five minutes before shutting them off (to let the turbos spool down) but we didn’t idle the non turbo 4JH more than a minute before shutting it down.

At this point, to try and deal with the glazing, you don’t have anything to lose in taking it out and running it hard for several hours.