Have these Yanmar Diesels a good reputation for reliability

[Wotname]

Originally Posted by Boxertwinjeff

Since salt water has inundated the engine would it now have a much
more limited life and should I avoid it ?
He will get back to me with a list of replacement parts and what exactly was done in rebuilding.

Not automatically, just be cautious. It really depends on how much water and for how long the water was in the engine.

[Boxertwinjeff]

Originally Posted by Wotname

Not automatically, just be cautious. It really depends on how much water and for how long the water was in the engine.

That will be a hard one to find out for sure, as I'm relying on the Seller's honesty. One thing is, between the boat needing Rerigging
and the ? mark over the engine at the asking price of $75,000, these points may deter a lot of potential buyers.

[Wotname]

Originally Posted by Boxertwinjeff

That will be a hard one to find out for sure, as I'm relying on the Seller's honesty. One thing is, between the boat needing Rerigging
and the ? mark over the engine at the asking price of $75,000, these points may deter a lot of potential buyers.

Maybe find out who did the rebuild and ask around about their reputation...

[sartorst]

Originally Posted by Boxertwinjeff

On further questioning of the owner he says it had 4200 hours up
before the rebuild, apparently Raw water siphoned through the exhaust manifold and into the engine,...he says caused by poor design of the
anti siphon valve, original design was a chamber above waterline with a
breather going down to the exhaust mixer box. He replaced it with an
an syphon valve positioned well above the water line....his words.
Since salt water has inundated the engine would it now have a much
more limited life and should I avoid it ?
He will get back to me with a list of replacement parts and what exactly was done in rebuilding.

Again not a fault of the manufacturer

[Emerald Sea]

We run 4JH5E's (54hp), 2013 models, and haven't had a whisper of an issue with them. They still have low hours at 850 each however Im religious about keeping the recommended servicing up and feeding them clean clean fuel. I hear the same from nearly all yacht owners with Yanmars. I had Yanmar Cape Town (Seascape) down this week for a complete service including valve lash adjustments (which Im not confident at performing yet) and they took oil samples which resulted in 'no findings'.

I don't find the parts excessively expensive, compared to Volvo's at least. We keep a pretty complete spares inventory on board however, simply as we are often in far away lands.

And thats unlike Volvo's, for which my last boat had installed and never never again. Constant problems - and IMHO, they just aren't built for tropical humid environments. Thats my experience with these engines.

If your Yanmar checks out with a reputable mechanic Im sure you wont go wrong.


Steve
L450
SV Emerald Sea

[Boxertwinjeff]

Originally Posted by Wotname

Way too soon IMO unless, of course, he was doing 2 or 3 hours a day, every day!

Sounds more like poor maintenance and he allowed the engine to swallow sone water or somesuch. Can you find out exactly what was "rebuilt"?
The parts usec would be good start and could tell us something useful about what was done!

Ok, Owner says " Head reconditioned, new valves & seals
Block bored 0.25 oversize
New Pistons & rings 0.25 oversize
New Bearings
New Starter motor & leads
Injectors tested & cleaned
Injector pump tested Ok, advised pump is very reliable
Receipts from Minards Diesel for $AU 2,938 for parts
Airlie Beach Cylinder Head Reconditioners did the Rebuild
Callaway Performance in Bowen did the Rebored the block
May 2014 replaced fuel lifter pump as it had a leak
Gearbox is a KBW20, has given no trouble"

[Wotname]

Originally Posted by Boxertwinjeff

That will be a hard one to find out for sure, as I'm relying on the Seller's honesty. One thing is, between the boat needing Rerigging
and the ? mark over the engine at the asking price of $75,000, these points may deter a lot of potential buyers.

Originally Posted by Boxertwinjeff

Ok, Owner says " Head reconditioned, new valves & seals
Block bored 0.25 oversize
New Pistons & rings 0.25 oversize
New Bearings
New Starter motor & leads
Injectors tested & cleaned
Injector pump tested Ok, advised pump is very reliable
Receipts from Minards Diesel for $AU 2,938 for parts
Airlie Beach Cylinder Head Reconditioners did the Rebuild
Callaway Performance in Bowen did the Rebored the block
May 2014 replaced fuel lifter pump as it had a leak
Gearbox is a KBW20, has given no trouble"

First up - disclaimer - I am more of a "shade tree" mechanic rather than a "real one"; so hopefully some professionals will chime in soon

The parts list match up with what might be expected at some water ingestion. It sounds like (IMO) that all the relevant bits were replaced.
This means the affected parts were replaced (and thus the "clock" has been reset on them) and the unaffected parts have about 5,000 hours on them.
This is (IMO) quite acceptable. You are buying a second hand boat and the engine was always going to be "used". You are getting almost new pistons, bearing and head.

As others have posted, the Yanmar injector pump is excellent and 5,000 hours is nothing on it - providing it has been feed clean fuel!

I totally trust Minards to supply Yanmar parts and I can't comment about the other organisations as I don't know them but someone in FNQ will know!

It also sounds like the seller is being open honest and has records to back up his claims - again a good sign.

Finally, a lot can be told just looking at the motor - is it clean and tidy and painted, are all the ancillary pipes and hoses and wiring looms looking clean, neat, un-cracked etc. The photo appeared to show reasonable care has been taken but sometimes hard to tell from a photo. The flexible fuel lines and water hoses shouldn't be too hard or too soft (mushy) etc.

Is the fuel tank clean (it you can tell that is), is there a glass bowl on the fuel filter and if, so, is it clean, does the fuel already in the system look OK, ditto the oil.

All of these will tell you in the current owner is fastidious or otherwise and also something about the other owners.

A fastidious owner will keep the paint up to the engine, others less so will allow the "unimportant" bits to rust etc. It is hard to tart up an abused engine in order to sell it .

Even how the cable tie ends are cut off tells you something .

From all you have posted about it so far, it seems pretty reasonable IMO and I would be happy to own it. The only downside (and a minor one IMO) is that you now have "used up" the option for fitting oversized pistons in the future but if you maintain the engine, you should never need them for at least another 10,000 plus hours.

Off-topic - your user name suggest that you might ride older BMW's - if so, that is a good thing

[med]

The Yanmar block will last pretty much forever. The weak bits are the starter motor (which is mounted very low down and will get sprayed with sea water if you have a problem with your shaft seal - guess how I know), and the heat exchanger which is only good for 20 years or so.

Otherwise give it clean fuel, change its oil from time to time, flush the cooling system every 10 years or so and they will go on forever.

[mjrgr8pain]

One thing I like about them, from the factory they dyno break in all their engines. My sailing instructor told us he loves delivering new boats with Yanmar engines because he doesn't have to worry about babying them if it looks like they might need full power.

Sent from my SM-G900T using Tapatalk

[TacomaSailor]

You describe the engine as a 50HP 4JH2CE

I am not familiar with that model number. Where did you find it?

The Yanmar website shows the older and discontinued 4JH2 models to be:
E 50HP
HTE 76HP
UTE 100HP
TE 62HP
DTE 88HP

The 4JH2 series was built 1989 thru 1999 except for the UTE which was introduced in 1991

I'm not sure the Ce designation is important but it would be good to know what kind of Yanmar you are buying.

Our 1994 4JH2E (50 HP) is running strong and clean after 2,850 hours. The maintenance cost has been minimal for 21-years.

Heat Exchanger and Injection Elbow $2,200
Replace all pipes and tubing in cooling system (raw and fresh) $150
Starter $500 (saltwater dripping on it as described by another post)
Waterpump $250

I was friends with a mechanic at the Tacoma, WA Yanmar dealership. They maintained "hundreds" of bigger Yanmars that were used in commercial fishing applications where the engine ran non-stop for 6-months at a time. He felt the engines were rock solid and easily maintained.

His only caveat was "run them hot and fast." They were designed to run at 70% - 80% of 25 hour rated RPM and need to be treated as high speed engines.

I am pretty sure any marine diesel, built since 1975 or so, is equally reliable if treated with care and operated as designed.

[Boxertwinjeff]

Originally Posted by TacomaSailor

You describe the engine as a 50HP 4JH2CE

I am not familiar with that model number. Where did you find it?

The Yanmar website shows the older and discontinued 4JH2 models to be:
E 50HP
HTE 76HP
UTE 100HP
TE 62HP
DTE 88HP

The 4JH2 series was built 1989 thru 1999 except for the UTE which was introduced in 1991

I'm not sure the Ce designation is important but it would be good to know what kind of Yanmar you are buying.

Our 1994 4JH2E (50 HP) is running strong and clean after 2,850 hours. The maintenance cost has been minimal for 21-years.

Heat Exchanger and Injection Elbow $2,200
Replace all pipes and tubing in cooling system (raw and fresh) $150
Starter $500 (saltwater dripping on it as described by another post)
Waterpump $250

I was friends with a mechanic at the Tacoma, WA Yanmar dealership. They maintained "hundreds" of bigger Yanmars that were used in commercial fishing applications where the engine ran non-stop for 6-months at a time. He felt the engines were rock solid and easily maintained.

His only caveat was "run them hot and fast." They were designed to run at 70% - 80% of 25 hour rated RPM and need to be treated as high speed engines.

I am pretty sure any marine diesel, built since 1975 or so, is equally reliable if treated with care and operated as designed.

The 4JH2CE 50Hp is in a boat I'm considering make an offer on,
the engine was apparently installed in 1999.

[Boxertwinjeff]

Originally Posted by Wotname

First up - disclaimer - I am more of a "shade tree" mechanic rather than a "real one"; so hopefully some professionals will chime in soon

The parts list match up with what might be expected at some water ingestion. It sounds like (IMO) that all the relevant bits were replaced.
This means the affected parts were replaced (and thus the "clock" has been reset on them) and the unaffected parts have about 5,000 hours on them.
This is (IMO) quite acceptable. You are buying a second hand boat and the engine was always going to be "used". You are getting almost new pistons, bearing and head.

As others have posted, the Yanmar injector pump is excellent and 5,000 hours is nothing on it - providing it has been feed clean fuel!

I totally trust Minards to supply Yanmar parts and I can't comment about the other organisations as I don't know them but someone in FNQ will know!

It also sounds like the seller is being open honest and has records to back up his claims - again a good sign.

Finally, a lot can be told just looking at the motor - is it clean and tidy and painted, are all the ancillary pipes and hoses and wiring looms looking clean, neat, un-cracked etc. The photo appeared to show reasonable care has been taken but sometimes hard to tell from a photo. The flexible fuel lines and water hoses shouldn't be too hard or too soft (mushy) etc.

Is the fuel tank clean (it you can tell that is), is there a glass bowl on the fuel filter and if, so, is it clean, does the fuel already in the system look OK, ditto the oil.

All of these will tell you in the current owner is fastidious or otherwise and also something about the other owners.

A fastidious owner will keep the paint up to the engine, others less so will allow the "unimportant" bits to rust etc. It is hard to tart up an abused engine in order to sell it .

Even how the cable tie ends are cut off tells you something .

From all you have posted about it so far, it seems pretty reasonable IMO and I would be happy to own it. The only downside (and a minor one IMO) is that you now have "used up" the option for fitting oversized pistons in the future but if you maintain the engine, you should never need them for at least another 10,000 plus hours.

Off-topic - your user name suggest that you might ride older BMW's - if so, that is a good thing

Thanks for your informative evaluation Wotname,...& yes I ride a Bmw
R75/5 1973

[med]

Originally Posted by Boxertwinjeff

The 4JH2CE 50Hp is in a boat I'm considering make an offer on,
the engine was apparently installed in 1999.

A new heat exchanger might be need some time soon.
Mine needs changing, and my 4JH2DTE is from 1998.

[TacomaSailor]

Originally Posted by Boxertwinjeff

The 4JH2CE 50Hp is in a boat I'm considering make an offer on,
the engine was apparently installed in 1999.

I have the Yanmar Service Manual for the 4JH2 series (A0A1029-9002) purchased from the Yanmar dealer in 2001. The models it lists are:
E
TE
HTE
DTE

The current Yanmar Parts Manual lists the following 4JH2 models:
E
TE
THE
DTE
UTE(B)

The engine in your photo does not seem to have a turbocharger so it must be the 2E because all the rest had various turbochargers and intercoolers.

Where on the ID plate do you see the designation 4JH2Ce?

The KBW20 transmission is the lightest/least strong gearset of all the 4JH2 transmissions and the manual says it should only be use on the 4JH2E.

The other big difference, for Yanmar engine reliability, is the KBW20 transmission DOES NOT mount an engine oil cooler. Two other transmissions used with the 4JH2 series (KBW21/KM4A) have engine oil coolers mounted.

The model designation on my KM4A transmission is hard to read and for years I thought it was the KBW20.

[George P]

Originally Posted by Boxertwinjeff

Hi, a boat I will be looking at soon has a 50hp Yanmar diesel, Model 4JH2Ce, don't know what year it was built, Owner says it was completely rebuilt in 2012 and has 645 hrs up. From photos & a survey report it appears to have been well maintained. Are they a good reliable engine?
and any ideas to what year it is? thanks for any replys...

It's a yanmar, best marine engine out there.