Yanmar 4JH3E

[svmarekova]

Does anybody have a torque specs for high pressure fuel lines on this engine? Thanks for any info.

[GreenWave]

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[svmarekova]

Unfortunately they don't show the torque for the box n ut at the high pressure fuel lines. But thank you for the information.

[GreenWave]

I have full shop and service manuals in PDF form but too big to post here. Send me email to kcollie820@earthlink.net and I can forward that to you.

[skipperpete]

Originally Posted by svmarekova

Unfortunately they don't show the torque for the box n ut at the high pressure fuel lines. But thank you for the information.

Interesting question svmarekova, you will need a crowfoot flarenut or OE wrench to fit the nut and it ( in some positions) changes the torque wrench reading. I can’t recall ever using a torque wrench on Yanmar injector pipe nuts other than the EU 4JH4E-TE With the injectors under the valve cover, but have frequently muttered curses when injector nuts have been overtightened in the past and the delivery valve holder tries to rotate with the nut.
As a guide, the M12 torque on the EU engine is 21.5 ftlbs +or- 3.5 ftlbs

[sailmontana]

Hello,
looking as though this is the page so far for my motors X 2 I was looking for high hour service advice. I've taken my Cat from a charter manager that didn't do his job (CC out of the BVI) and need some input for these motors.
If you (very skilled and knowledgeable) were to take ownership of twin 4JH4E's what would you do not knowing the actual hour count (at least 7000) and have faith that they can run another 2-3K. Start every time with barley a turn and NEVER smoke.
Other than the usual 100 hour stuff what needs to be done so I know that it's been done?

Change all fluids, raw water exhaust elbow inspect/replace, Injector pump rebuild, injector sync...ect please add to this as you see fit...for all to learn from your expertise!

Know that I realize that this is an "open forum" so please be kind. I am just a bit shocked by what some people say in response to what may seem to some an annoying question but to the asker a need. I find that even though a non-religious follower, "The Golden Rule" can go a long way.

Thanks in advance,
J-

[skipperpete]

Just to be clear, is this is the 16 valve model with the injectors under the valve covers and the Bosch VE injector pump ? Shaft or Saildrive. Assuming it’s the 16 valve model you definitely need to adjust the valve clearances and the bridges but make sure you have some spare soft rubber seals for the injector pipes, they tear very easily and must be prized out to lift off the valve cover. This is about the only Yanmar that has an above normal risk of fuel oil/ lube oil contamination from the internal fuel plumbing so care is needed with washers and connections. At 7,000 hrs I’d be wondering about the condition of the drive plates. All the things you mention are what I’d be doing but I’d be hesitant about rebuilding the injector pumps, those VE’s are very reliable, possibly the best rotary pump ever. Also do a check on the circulating pumps for noisy bearings, looseness or leaks from the shaft seal.

[Ericson38]

Originally Posted by skipperpete

Just to be clear, is this is the 16 valve model with the injectors under the valve covers and the Bosch VE injector pump ? Shaft or Saildrive. Assuming it’s the 16 valve model you definitely need to adjust the valve clearances and the bridges but make sure you have some spare soft rubber seals for the injector pipes, they tear very easily and must be prized out to lift off the valve cover. This is about the only Yanmar that has an above normal risk of fuel oil/ lube oil contamination from the internal fuel plumbing so care is needed with washers and connections. At 7,000 hrs I’d be wondering about the condition of the drive plates. All the things you mention are what I’d be doing but I’d be hesitant about rebuilding the injector pumps, those VE’s are very reliable, possibly the best rotary pump ever. Also do a check on the circulating pumps for noisy bearings, looseness or leaks from the shaft seal.

I'm pretty sure the 16 valve model is the 4JH4.

[skipperpete]

Sail Montana’s post #6 referred to the 4JH 4E..... not the OP’s primary 4JH3E title.

[sailmontana]

Thanks,
as always, love this place!
They are 2006-ish 4JH4E's, that's a little past my knowledge since I'm not at her currently.
Figured that they were pretty close or close enough to warrant the same high hour parts and attention. I can post a picture of the engine plate if that helps.
Also upgraded the SD's to 60's, very excited about this since it was a "job of jobs's" I'm told by the experts at Yanmar SXM. Had to cut off the Port side drive shaft (seized inside SD head), engine beds ect to then re-glass and remount all the "permanent" parts. Custom backplates from FKG, you name it, we did it. I can smell her new bilge paint when I enter the yard...smells like money. I'd rather not do that again.
When both engines were out they gave them a looksie but not as extensive as I would have wished. Shaft seals were replaced and all new sensors added for new control panels. They weren't "tuned" though. Thought I told them to do that but the bill didn't mention it. Up to me now, they ain't coming out till they get tossed.
J-

[skipperpete]

Ouch, that’s a hard way to extract a Saildrive. I had the same problem with the splines on a gearbox attached to a 4JH-E but was able to open up a gap between the housings enough to get a thin flat bent ring spanner onto the drive plate bolts and then cut the spline hub in half with an angle grinder when they were separated. It’s good that you changed the saildrives, the SD50’s had some vulnerabilities.
It sounds like your engines have been in the care of an actual Yanmar dealership rather than a charter fleet serviceman so that’s a good sign (although having raw water in the flywheel housing raises questions.... the rear main oil seal should have been changed too)
The 4JH4 series is a bit confusing, there was a 4JHE, 4JH4AE, 4JH4E, 4JH4TE and 4JH4 HTE, all good engines and very similar but my least favorite is the 16 valve head TE, mainly because of the extra care needed with the adjustments and the potential for an internal fuel leak which can seriously harm the engine. The VE fuel pump is a winner, it’s probably the most common HP pump across the entire diesel engine market and any ol tech shop can fix em BUT the MP2 pump seems to be Yanmars own creation and should best be serviced by a Yanmar certified pump tech.

[Ericson38]

On the 4JH2 series, there is the E (non turbo), the TE (turbo), HTE (turbo with intercooler and water jacketed turbo housing), and DTE (higher boost of HTE version). Original 4JH is 1.6 liter, 4JH2 is 1.8 liter, and 4JH3 series is 2.0 liter. All two valves per cylinder.