Yanmar 4JH57

[HKTim]

I need some help to ask Yanmar some smart questions about my 4JH57 Common Rail engines.


My Leopard 48 cat is being from Cape Town as I type. About 2/3s of the way into the +6000 nm delivery, the crew had to stop and get a Yanmar tech to look at the engines. Apparently the engines were cutting out every 40 -120 minutes. Engine temperature was fine and no sign of water in the fuel. Yanmar put some new fuel filters on and everything seems to be fine and the boat has left port and is on her way for the final stretch. Arrival is expected to be September 22.


I have not had the opportunity to speak directly with the delivery crew but am surprised that they would not have spare fuel filters on board for a +two month trip. So I am worried this is not just a problem about the fuel filters. More importantly I am worried that in the run-up to bringing the boat into port for repairs, would there have been any more serious damage done. Fortunately, the next two weeks will be a good test for that question.


I have read a lot about the fragility of common rail engines and fuel filtering. If the filters were the only problem, is there any risk that water or sentiment could have gotten past clogged filters and done more damage?


The engines will have a 2 year or 2000 hour warranty once the boat is signed over to me in a few weeks. But I'd like to make sure I really understand the problem experienced and implications for the engines now and down the road.


So if any mechanically minded owners out there can share some questions you think I should be asking Yanmar, please send them.


Thanks very much,


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[Emerald Sea]

The Yanmar techs that worked on the repair should of advised specifically what the problem was? It could be a mirage of things, you need a report from them.


Steve
L450
SV Emerald Sea

[DeepFrz]

I would think that you should contact Robertson and Caine. Aren't they the ones that are responsible for the yacht delivery? I would ask for a detailed report on what exactly the engine issue was and what was done to complete the repair.

Fishing in CF for impossible answers isn't going to help you.

[stefano_ita]

up

what happens at the end?

thinking about my nex boat...4jh57 common rail or 4JH5mechanical 53hp..

do you think is quite silence engine? what about fuel consumption?


do you have a specsheet that show the gr/kw hour? i can't find on any website..

p.s. compared right now with the nanni diesel n4.50...the nanni is indirect injection..more efficient on every rpm...

[a64pilot]

I know a little about common rails, the major advantages of common rail is that it's dead easy to change injection timing and pulse width, plus you can do some slick things when you control injection with electronics, like a little shot of fuel just prior to the main injection event so the flame front is already established when the main fuel shot get there, so the Diesel "knock" is almost eliminated, very fine control of injection can be achieved.
Fuel sensitivity come from extremely high fuel pressures, and very tiny holes in the injectors the fuel flows though.
Parts cost alone to change the injectors in my Duramax Diesel was around $3,500 I think.
Common rails are usually Direct injection Diesels although they may be IDI and inject in a pre-combustion chamber also, could be either.
I seriously doubt your engines have been hurt, my 2001 truck is common rail, it's no longer new tech and the problems are mostly solved I'm sure.
The things that are possible with common rails are amazing compared to old mechanical injection.


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[HKTim]

Still not resolved. Yanmar Malaysia "fixed" the problem with new fuel filters. 100 miles out after that and engine started to cut out again and remained that way for remaining 1500 miles to Hong Kong.

Yanmar Hong Kong has said its a fuel delivery problem but says it's not a problem with engine so not their responsibility. So trying to get someone to accept responsibility still. Disappointed that yanmar did not do a electronic diagnosis of engine. Been told that should have happened. But local yanmar agent just said they think their is air getting into fuel and walked away. No further follow up. So now asking builder in South Africa if there might have been problems with installation.

On a related note my old boat (L46) had the 54 hp model with Bruntons folding props. New engine has same props. But I've noticed the new boat has much less "bite" then the old one when motoring. Especially in reverse. Different hulls obviously. But the difference is obvious.

Regarding noise, a bit quieter but not materially.

I have not had a chance to run the boat enough to comment on fuel consumption. But at the same rpm, the yanmar spec sheets indicate the old 54 hp model is more fuel efficient. But you get higher torque at lower rpm with new engine so some trade off. New engine does have nice instrumentation to provide data about actual fuel consumption in litres per hour.



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[stefano_ita]

Originally Posted by HKTim

Still not resolved. Yanmar Malaysia "fixed" the problem with new fuel filters. 100 miles out after that and engine started to cut out again and remained that way for remaining 1500 miles to Hong Kong.

Yanmar Hong Kong has said its a fuel delivery problem but says it's not a problem with engine so not their responsibility. So trying to get someone to accept responsibility still. Disappointed that yanmar did not do a electronic diagnosis of engine. Been told that should have happened. But local yanmar agent just said they think their is air getting into fuel and walked away. No further follow up. So now asking builder in South Africa if there might have been problems with installation.

On a related note my old boat (L46) had the 54 hp model with Bruntons folding props. New engine has same props. But I've noticed the new boat has much less "bite" then the old one when motoring. Especially in reverse. Different hulls obviously. But the difference is obvious.

Regarding noise, a bit quieter but not materially.

I have not had a chance to run the boat enough to comment on fuel consumption. But at the same rpm, the yanmar spec sheets indicate the old 54 hp model is more fuel efficient. But you get higher torque at lower rpm with new engine so some trade off. New engine does have nice instrumentation to provide data about actual fuel consumption in litres per hour.



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wait do you have bruntons autoprop with 57 hp yanmar?

if yes please tell me diameter? how much did u payed it? boat length, weight, gearbox ratio...and fuel consumption at cruise speed

and nothing else

[HKTim]

The boat I have now is a leopard 48. The previous was a leopard 46. Both have same folding props from Bruntons. Don't have all the tech specs on hand though.

Boat is still being commissioned so I've not had her out to actually provide info about fuel consumption.


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[stefano_ita]

Thanks np��

[HKTim]

Finally had a chance to take the boat out and push the engines a bit. Max RPM is 3000 on this engine. After 5 minutes at 2500 rpm, the temperature alarm went off on the port engine. Temperature was 95 degrees C. Starboard was 91 degrees C. Engine had been serviced a few hours earlier. So plenty of coolant and water flowed fine at exhaust. Had yanmar tech onboard. He said he's seen it before and believes it can be fixed with a "wire". Not at all sure what that means. He was going to discuss with yanmar first and get back to me. He also thinks there is still air getting into fuel system.

On a side note i asked yanmar if it would be okay to add startron fuel tank cleaner to my tanks. He said don't use it. Injectors are too sensitive. So not sure if there is anything I'll be able to add to my tanks to control bug growth now.


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[a64pilot]

I would definitely use a bio-cide in my Diesel, to not use it is foolish in my opinion.
Asking for trouble

[Tayana42]

Most fuel docks in my area sell diesel with biocides already blended in the fuel. I've not had any growth in my tanks in the 16 years I've owned this boat. Have I just been lucky? Should I add additional biocide?


S/V B'Shert

[robertevans]

Originally Posted by HKTim

Still not resolved. Yanmar Malaysia "fixed" the problem with new fuel filters. 100 miles out after that and engine started to cut out again and remained that way for remaining 1500 miles to Hong Kong.

Yanmar Hong Kong has said its a fuel delivery problem but says it's not a problem with engine so not their responsibility. So trying to get someone to accept responsibility still. Disappointed that yanmar did not do a electronic diagnosis of engine. Been told that should have happened. But local yanmar agent just said they think their is air getting into fuel and walked away. No further follow up. So now asking builder in South Africa if there might have been problems with installation.

On a related note my old boat (L46) had the 54 hp model with Bruntons folding props. New engine has same props. But I've noticed the new boat has much less "bite" then the old one when motoring. Especially in reverse. Different hulls obviously. But the difference is obvious.

Regarding noise, a bit quieter but not materially.

I have not had a chance to run the boat enough to comment on fuel consumption. But at the same rpm, the yanmar spec sheets indicate the old 54 hp model is more fuel efficient. But you get higher torque at lower rpm with new engine so some trade off. New engine does have nice instrumentation to provide data about actual fuel consumption in litres per hour.



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I find it amazing that for the time it would take to pressure the fuel system, to find the air leak and fix the leak that yanmar did not fix this and send Roberts and Crane a bill for an hours labour, but would rather leave someone stuck.

[gmnord]

I have a 40 ft ketch in the Eastern Carribean, and had installed a new Yanmar 4JH57 in January 2020. The installation included a priming bulb in the fuel line near the engine fuel filter, for priming fuel after servicing the engine.

Running the engine from St Lucia to St Vincent, and later from Mayreau to Carriacou, we encountered a problem with the engine losing fuel pressure at sea, usually above 2400 RPM and often in a 1 -2m sea. I could pump the bulb 3 or 4 times and restart it, but it would fail intermittently in these conditions (but, not in an anchorage at 1600-1800 RPM in flat seas).

We deduced that the problem is that this Yanmar engine has some less than robust fuel pumps (a priming pump and a common rail pump, made by Bosch for cars). In our case, the engine must pull fuel vertically about 1.5m, and laterally about 3m.

We recently installed an auxiliary electric fuel pump between the Racor water separator and the engine fuel filter, removing the priming bulb, and that has fully remedied the problem. The engine has performed without issue in sea trial outside Tyrell Bay and from Carriacou to Prickly Bay, Grenada.

The pump we installed is a Walbro FRB 13-2 Marine Diesel lift pump, which is variable pressure based on engine demand. This pumps at 6-8 PSI and can pump up to 45 GPH - vastly more than the roughly 1/2 gal per hour our engine uses.

We presently connected the pump to 12V DC at an unused switch at the helm, but will later connect it directly to the POWER switch on the Yanmar console, so that the pump is on whenever power its on to run the engine.

This problem may occur only for long fuel lines that pull fuel relatively high (e.g., more than 1m) from the tank. But given the apparent dicey capabilities of the engine fuel pumps, I would say for the roughly US $200 to install an aux pump like this, one can buy some comforting confidence that the engine will not fail at sea for pumps not able to provide sufficient fuel to the engine.

[more]

Originally Posted by HKTim

- Had yanmar tech onboard. He said he's seen it before and believes it can be fixed with a "wire". Not at all sure what that means.
-He also thinks there is still air getting into fuel system.

yes lot diesel engine have problem with cheap chinsed fake tined wire connector. but tin price start droping from 50000$ to 30000$. i have huge problem on couple new boot, learn quick lesson. simple spend 50 hour work tried everything on brand new yacht only delivered from france to croatia. couple connector oxide inside and we dont see on first ,we demolished half boat removed diesels tank .


air getting into fuel. easy repair.

check all hose, bla bla bla
but most important locate pre-filter racor 2 micron couple cm+ over high pressure yanmar pump.
if you have lekage air in system he stuck in racor prefilter use racor 500 900
bigger better but racor 500 is overkill he can stop 1 liter air before come in fuel filter of engine.

fuel filter of engine is yanmar problem in warranty