burgundyben
Well-known member
Your use case might be an outlier.
Yanmar engine issues
- Thread starter Rhubarb
- Start date
Your use case might be an outlier.
greeny
Well-known member
"Allegedly" haha. Maybe they've all got the problem but not reported it. Maybe they think it's normal and don't know any different. It would be great if you could talk with some of them and ask the question directly to other owners.
I doubt the "big boys" in the company would be involved if it was only one installation. If it is an issue affecting all the installations then probably talking pots of money to sort it out and make the necessary modifications whatever they turn out to be on all boats. Sounds like retrofitting a smaller alternator i.e. go back to a proven system would be the cheapest and easiest way to go for them, or fitting a "soft" start/ override system on the alternator may be an option as has already been discussed on here. But first need to clarify that it is a design error on all boats not just something on your's in isolation. Hope you get it sorted soon but these things take time when they get up to corporate level.
Rhubarb
New member
You have a way of summing things up nicely.
If anyone knows any Jeaneau 319 or 349 owners then perhaps they could direct them to this thread.
Rhubarb
New member
I just thought I’d drop you a line regarding the resolution to the problems I was having.
The basic problem was that the Yamaha 3YM20 engine was upgraded from having a 60/80 amp alternator to 125 amp alternator. If the batteries were slightly depleted then the alternator would endeavour to deliver 125 amps to the batteries and amazingly stop the engine from revving. In the old days the alternator was de minimis to the output of the engine, but not anymore, apparently the tail is now wagging the dog.
Needless to say Yanmar/Barrus were useless B£$%&*ds and Jeanneau didn’t care.
The Jeaneau broker eventually fitted 2 Victron 50A DC-DC buck boost systems which effectively isolated the domestic batteries from the alternator at startup and only allowed 20amps to be output at idle speeds and a maximum of 70amps when revs have exceeded 2000revs for more than a minute (measured by voltage output of the alternator).
It was interesting to note that if the batteries were allowed to take 30amps at the idle speed it was sufficient to slow the engine revving when the engine was cold.
Happily for us the boat is now working as expected. But I thought I would let you know the outcome in case you come across any similar issues.
The basic problem was that the Yamaha 3YM20 engine was upgraded from having a 60/80 amp alternator to 125 amp alternator. If the batteries were slightly depleted then the alternator would endeavour to deliver 125 amps to the batteries and amazingly stop the engine from revving. In the old days the alternator was de minimis to the output of the engine, but not anymore, apparently the tail is now wagging the dog.
Needless to say Yanmar/Barrus were useless B£$%&*ds and Jeanneau didn’t care.
The Jeaneau broker eventually fitted 2 Victron 50A DC-DC buck boost systems which effectively isolated the domestic batteries from the alternator at startup and only allowed 20amps to be output at idle speeds and a maximum of 70amps when revs have exceeded 2000revs for more than a minute (measured by voltage output of the alternator).
It was interesting to note that if the batteries were allowed to take 30amps at the idle speed it was sufficient to slow the engine revving when the engine was cold.
Happily for us the boat is now working as expected. But I thought I would let you know the outcome in case you come across any similar issues.
SaltyC
Well-known member
Hmmmm . I have a Yanmar YJH4E which was upgraded from Circa 60Amp to 125 Amp alternator.
Although the engine doesn't have a problem, the drive belt does. the excesive wear and black dust everywhere is a major concern.
My local Yanmar dealer stated, they 'eat' drive belts??????
Although the engine doesn't have a problem, the drive belt does. the excesive wear and black dust everywhere is a major concern.
My local Yanmar dealer stated, they 'eat' drive belts??????
John_Silver
Well-known member
The 3YM20 on Stargazer (Rassy 310) is driving a 150 amp Balmar, without issue. And the standard Yanmar alternator, which the Balmar replaced, was rated at 125 amps. (Engine fitted 2019). Supporting the alternator red herring theory….
Edit: read the thread to the end now! We must just be lucky that we’re not afflicted! Or, the Merlin charge management kit is preventing the issue.
PS As supplied (ie without any intervention from the Merlin) my new 3YM stops the alternator coming under load until around 1800-2000 rpm. Whereas the previous 3YM (2009 vintage) let an 80 amp Balmar charge from tickover. A friend, who also re-engined a Yanmar, also remarked on this. Now I know why the feature is there: must be to cope with bigger alternators potentially sapping forward motion.
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SaltyC
Well-known member
What drive belt do you have?
John_Silver
Well-known member
The ‘new’ 3YM came with wide (20mm) ribbed pulleys. For ‘micro v’ belts. Actually car ‘stop-start’ alternator belts. No black dust and, although I do change them annually, they don’t look worn.
Whereas the ‘old’ 3YM had those deep narrow (maybe 5mm) belts, sitting in a deeply v’d pulley. (Apologies- don’t know the technical terms!). Even with an 80 amp alternator there was black dust everywhere. And by the end of the season, cracking on the outer surface of the belt….
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SaltyC
Well-known member
I have an 'older ' 4YM4E with the narrow deeply vee'd belt and a 130A alternator.
An appetite for drive belts and black dust everywhere.
An appetite for drive belts and black dust everywhere.
WindyWindyWindy
Active member
With upgraded alternators on this engine you will likely need a pulley/belt upgrade as well. The alternator belt also drives the fresh water pump and if its hot then the engine will overheat quickly if it fails.
Porthandbuoy
Well-known member
My 4JH3E fitted with a Belmar aftermarket alternator (I think it’s ~100A) wore the belt away at an alarming rate. Black dust everywhere and had to adjust it frequently. Swapped it for a Gates cogged belt. No more black dust and I haven’t had to adjust the tension all this year.
rotrax
Well-known member
We have the 110BHP Yanmar 4JH4-HTE Tubo engine. After we bought it it also ate belts and covered the engine and engine bay with black rubber dust. Those who know me and our boat will be aware of how much this pissed me off. The dealer recomendation was to blue the dosh and upgrate to wider pulleys and a serpentine grooved belt. This fix works but can be expensive.
My fix, however, was to use Genuine Gates belts with the notched inside run.
Once a new belt is bedded in it appears to last for ever. Current belt 3 years old, not required adjustment for 300 hours.
We have a Balmar 110 AH Alternator and Balmar smart regulator with 'soft start' feature.
The red charging light takes 30 seconds before it goes out as the regulator energises the field coil in the alternator slowly.
IMHO, Yanmar are at fault for specifying an unsutable belt as a spare part.
Gates belts are far cheaper and far, far better!
I totally agree about the lack of expertise and knowlege within the Barrus Yanmar department. They recomended me a dealer to assist with my enquiry as they did not even understand what I was talking about. A basic job, removing the injector pump.
Having been in two Tech Services departments for a major Automotive manufacturer and ditto a Motorcycle manufacturer I was appalled! I knew the products I was responsible for inside out and kept abreast of 'real world' service problems through regular contact with our dealers and distributors.
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scottie
Well-known member
regarding belt cost I doubt that many pay less than an organisation like Yanmar however retail prices are quite something else
Yanmar can make Penta extremely affordable
Yanmar can make Penta extremely affordable
jwilson
Well-known member
When 3YM30s were a new model in 2004.5 Barrus claimed absolutely no knowledge of overheating of new engines - first reported in warm water Florida with engines days old. Then the same started to happen with UK engines. Mine overheated at 50 hours on the engine. Eventually they admitted the the first 5,000+-odd engines supplied had heat exchanger cores that were inadequate, and eventually and grudgingly supplied under warranty better ones. But they never did contact every buyer: just waited till people complained. So possibly 1,000+ owners of new engines who only ever ran at lowish revs never found out till the day they HAD to run at 75% of max revs to get home in bad weather or pushing a tide.
Not my idea of a good company. Pity, as in many ways Yanmar are good engines.
SaltyC
Well-known member
Hmmmm. Sinking rapidly. Following Porthandbuoy and your responses.
Followed the link on the former, length and width easy to detrermine, angle ??? not sure. However, I will now persue. I too HATE clearing the black dust.
After a Volvo 2020, which in 12 years I never needed to replace the belt, the Yanmar is 'wrong' is it due to builder 'upping' the alternator from circa 6o to 130 Amps? Who knows but it is a constant worry.
rotrax
Well-known member
In the 1970's I was I/C a Suntester rolling road dynamometer at the BLMC Service School at Cowley located in the Carburetor and Tuning workshop.
A Jaguar car with all the electrical gear flat out-headlamps on full beam, heated screen, heater flat out, wipers flat out, hazard warning lamps, stoplamps etc. lost 5 BHP driving the alternator to keep up with the current draw.
The alternators field coil becomes highly magnetic and does not want to rotate.
That is what shags the belts out.
Those with a notched inner are tighter around the small diameter alternator pully, allowing the alternator to be driven at high output without excessive belt slip. Without the notched inner, internal stress within the belt as it tries to make a shape around the small pulley does not allow enough belt grip in that most important area.
From direct experience.
Yanmar belts slipped and failed soon after fitting. Gates belts did not and proved very durable.
The only difference is the internal notches on the Gates belt.
A Jaguar car with all the electrical gear flat out-headlamps on full beam, heated screen, heater flat out, wipers flat out, hazard warning lamps, stoplamps etc. lost 5 BHP driving the alternator to keep up with the current draw.
The alternators field coil becomes highly magnetic and does not want to rotate.
That is what shags the belts out.
Those with a notched inner are tighter around the small diameter alternator pully, allowing the alternator to be driven at high output without excessive belt slip. Without the notched inner, internal stress within the belt as it tries to make a shape around the small pulley does not allow enough belt grip in that most important area.
From direct experience.
Yanmar belts slipped and failed soon after fitting. Gates belts did not and proved very durable.
The only difference is the internal notches on the Gates belt.
