Yanmar 4JH2-UTE 100hp Turbo Diesel

Does anybody have experience with this engine? We're going to have a look at a 30' trawler in a couple days, and there seems to be precious little information on the net about this particular Yanmar...not a good sign...

The boat is of 1982 vintage, the Yanmar is 1995, and apparently the boat hasn't been out of its slip at the marina for 2 years since the original owner passed away.

I'm curious to find out what the person selling it has been doing to keep the engine maintained...what are your thoughts regarding that?

MurrayM,
The 4JH has a really excellent rep in NA 55hp version and I'll bet the turbo is good too. Is it aftercooled? I had a 3 cyl HM Yanmar and it was excellent. Lots of guys don't like the higher rpm of some of the older engines but I don't think it matters.
What kind of boat is it?
And where on the coast are you. We just did the whole BC coast coming down from Alaska.
One passing thought is that my Yanmar had an awful transmission .. a Kansaki. Rough shifting and VERY noisy. I'd not want one of them.

Hi there,

I'm in Kitimat, BC. Can't wait to do the BC coast in "trawler style" as the last time my wife and I did the BC coast, it was by sea kayak. We're looking forward to heading north to your waters as well. So much to discover!

We're diesel rookies. As newbie as it gets. A quick google search about this engine and aftercoolers brought up this confidence boosting nugget from boatdiesel.com;

"I just had the opportunity to dissasemble an aftercooler on a 4JH2-UTE that I've been watching over(not in charge of)for about 6 yrs.. This particular engine is the 100 HP version but is re-governed to operate as a generator engine at 1800 RPM (kinda like running slow)..This engine has had a multitude of problems over the years but NONE of them have been Yanmar's fault.. About 2 yrs ago, a fitting broke or something and it lost all of the coolant.. The engine continued to run until it seized (or very close); the shut downs didn't work... This happened at about 8000 commercial-type hours.. Well, we freed up the engine and got it running w/o taking anything apart and the engine would run "so-so" but with lots of crankcase bypass and was using coolant.. After a few oil changes the engine seemed to heal itself and has operated well for the last 3000 hrs or so..Scuffed a piston/ stuck a ring/ cracked a manifold or blew a head gasket?? It really should have done a few of these things..Last week it started running crappy again and we dumped some "Rislone" in the oil and the owner put some stuff in the fuel... Anyway it's running good again but suggested that he service the aftercooler and heat exchanger for the first time.. All I can say is that these components are of first class design and are far superior in construction and design than the newer high HP propulsion engine and to anything my favorite manufacturer (Cummins) puts on their B's and C's..What really blew me away was how clean the saltwater cooled aftercooler was after 11000 hrs in a nasty wet environment... My hat's off to Yanmar on this.. Too bad they don't employ this type of design in the LY's and LP's...The (older?) 4JH is an incredible motor and just about reminds me of a 6-71 Detroit as far as reliabilty goes.....Yanmar and (Cummins) Are you listening?? Tony"

We'll get the fellow to fire it up, and see how it behaves. It'll also give us a chance to see if he increases the RPM's to burn off carbon after running it at low RPM's.

The trawler quest continues...

"I'm curious to find out what the person selling it has been doing to keep the engine maintained...what are your thoughts regarding that?"

The FIRST question that should be asked of any used boat!

Best case, the person watching the boat for the past 2 years did NOTHING for those 2 years ,

However should have he pickeled the engine BEFORE the sit, preserving oil for the lube oil and preserving fluid in the fuel injectors and pump.

The cylinders fogged.

Intake and exhaust sealed as air tight as can be done.

The fuel tank should have been emptied and left dry.

Or filled by hand to the brim.

Unfortuniatly many folks will not have the time or money to take care of a diesel that is out of service.

The worst "cure" is some pal that comes and cold starts the engine once a month or so idles it for a half hour (wont warm up with no load even in 10 hours) .

Abondoning a diesel is "Much Ungood".

FF said:

However should have he pickeled the engine BEFORE the sit, preserving oil for the lube oil and preserving fluid in the fuel injectors and pump.

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The Yanmar Operation Manual for JH(2)'s is specific about what to do before long term storage...with prospective buyers showing up at irregular intervals, and the boat never leaving the marina, I'm pretty sure those steps haven't been taken.

Here's Yanmar's advertising / spec sheet;

http://www.yanmar.com.au/media/35529/4jh2-ut(b)e.pdf

manyboats said:

Is it aftercooled?

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"Turbo + intercooler"

For anybody researching this engine in the future (gotta love computers) here's Yanmar's operators manual;

http://www.yanmarmarine.com/theme/y...nes/Operation-manuals/JH(2) OP Manual-ENG.PDF

Either Stryker's out of Port Hardy or Shearwater should have a good diesel, hull and systems guy to look over the engine and other systems on the vessel. More to it than the Yanmar to consider. Get it hauled to do a good survey.

sunchaser said:

Either Stryker's out of Port Hardy or Shearwater should have a good diesel, hull and systems guy to look over the engine and other systems on the vessel. More to it than the Yanmar to consider. Get it hauled to do a good survey.

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You bet. My eyebrows went up during our phone conversation when he said the zincs haven't been changed since it was last bottom painted in 2009. Could get interesting...

"The Yanmar Operation Manual for JH(2)'s is specific about what to do before long term storage.."

Most MFG will have a specific set of requirements for Out of Service.

Hopefully the owner read the book.

Best that can be done with an in use boat is to simply USE IT!

Taken for a spin at good load for an hour or so once a month will take care of many of the problems.

One of our yacht club members bought a brand new Ranger tug with that engine. Took it to Catalina and the engine "ate itself" coming back at only 68 hours. Yanmar made good on it with another new engine.

ancora said:

One of our yacht club members bought a brand new Ranger tug with that engine. Took it to Catalina and the engine "ate itself" coming back at only 68 hours. Yanmar made good on it with another new engine.

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Yikes!

This one's got 1,900 hours, so hopefully it's past the self-cannibalistic stage...

Yanmar made good on it with another new engine.

Probably one of the Toyota conversions , the newer BMW are more robust.

The owner of the Ranger is a "check-writer", doesn't know an injector from a lift-pump. He was told by Yanmar that an oil-line failed and that there was a recall on that engine.