Yanmar 4JH4E and Balmar alternator fit woes

[hlev00]

I ordered a Balmar Series 60 100A alternator kit for my 4JH4E. I went for the V belt version thinking that I could modify my Yanmar/Hitachi as a backup. The problem I am running into is that the Balmar doesn't fit with the standard Yanmar V belt. Balmar support is scratching their heads because so many of these have been installed successfully. I may just bite the bullet and buy the serpentine upgrade, which I realize now is the way I should have gone. At least others that have installed Balmars used them successfully. However time is a bit tight and I'd like to get the current setup to work.

Using the standard Yanmar V belt I ran into two problems. First the alternator compresses the freshwater hose that runs next to it. The original alternator was always close. The original is 4.6" in diameter and the Balmar is 5.35". Enough to cause a problem. The second problem is that the dog leg of the Yanmar tension arm runs into the mounting tab on the top of the alternator. One friend with the same engine simply cut the part of the mounting tab off and moved the cooling hose. That will work but Balmar has never heard of such drastic measures being needed so I hope I am missing something.

Second thought I had was to try one belt size up. Autozone cross referenced the Yanmar / Mitusbishi part to a 44" V belt, and so gave me a 45" V belt. I took a 46 and 47 as well but those weren't needed. Things looked great except now the belt is very close to the seawater pump with only about 1/8" clearance. Things ran okay but after 20 minutes or so there was a lot of belt dust, especially near the seawater pump. My guess is that the vibration of the belt was enough to rub against the pump, slowly scraping bits off. It is possible that the Autozone belt was just too low quality. I am trying to source a Gates or Drayco to test too.

Last thought is that the original belt isn't really 44" but 43, or maybe a metric version. Maybe a 44.5" belt exists to purchase.

In the attached photos, one shows a mounting hole indicated by a yellow arrow. I suspect repositioning the tensioner arm to this will help if not solve the problem dog leg of the tensioner hitting the alternator. This won't fix the problem of the coolant hose being compressed. My friend repositioned the hose on the bracket with the red arrow to get some more space.

I am hoping someone here has encountered this situation with the V belt before and can offer a solution, or confirm that in addition to fixing belt dust, the serpentine kit is the only way to solve the space problems.

Thanks,
harry

[NYSail]

Ain’t she pretty......4JH4E 150 amp alt backed down to 120..... no dust, smooth operation, chicks dig it!

[a64pilot]

Bite the bullet and go with the serpentine belt, cause unless you turn that 100 amp way down, it’s going to dust, and even then your going to have to run it so tight it’s not the best thing for bearings and you’ll always be messing with the belt.
A serpentine, is install and forget.

[NYSail]

What I find with all the boats I’ve owned (3) is that modifications away from the manufacturer is necessary. Balmar has never heard of a thing like cutting the bracket to fit an engine yet balmar (dale) who are great people won’t tell you to set the mc614 regulator bulk and absorption amp and time levels to battery manufacturer specs. I first went balmar way.... then Maine Sail told me correct settings and alt worked 100% better. Factor settings on the regulator are 19 minutes bulk, 19 minutes absorption then to float...... my 500 amp bank will never charge listening to that. Now with Maine sails advise I stay in bulk and absorption much longer at higher voltage (to match battery specs) and batteries love it (and so does my cold beer). We on our boats are real world and have to adjust and set things accordingly.

[hlev00]

Originally Posted by NYSail

Ain’t she pretty......4JH4E 150 amp alt backed down to 120..... no dust, smooth operation, chicks dig it!

Hey! Thought I might see you here. And she is!

[NYSail]

I learn so much from all these forums! Hope you stop by LI on your way south.....

[NYSail]

And get the serpentine belt...... it really is the way to go. My previous engine was a Yanmar 3HM35f..... I put a 70 amp balmar alt with extrnal regulator. I never downgraded the alt running at full 70 amp. I had major dusting issues..... a mess. I downgraded alt and still dust plus now belt issues. Serpentine you will love. Also with our engine it is a simple swap..... I ordered my alt with the kit so it came with the serpentine pulley already attached but I’m sure it’s not to hard to switch pulliesi.

[Alita49DS]

I endorse everything that others have said about getting a serpentine belt. Even with a standard alternator, on a Yanmar the dust and belt wear with a V belt is a complete pain. I blame Yanmar for not themselves having designed the thing properly. At build the difference in cost must be minimal.


One word of caution which may not apply to the 4JH4E but did apply to my 4JH3-TE: check the exact size of the flywheel before you order the kit. The one that originally came from Electromaax did not fit mine. Might have been a whisker, but was enough to prevent the new pulley seating. To give Electromaax their due, they sorted it out very efficiently. An excellent company and, I believe, significantly better value than Balmar. The latter probably cashing in, Apple like, on their trade name.

[NYSail]

The balmar serpentine kit for the 4JH4E fit like a glove and was easy to install.

[hlev00]

It’s in for a dry fit but still seems too tight. Against the fresh water hose and that is after removing a bracket that secures the fresh water piping. Now fresh water hose could vibrate against the belt.

Maybe a few more adjustments then it’s coming out.

[amaka101]

Hi,
I have a 4jh5e & I was wondering if anyone could let me know if this system would accept a 120A Bosch alternator.
thanks

[Matt Johnson]

We had belt dust issues too with NAPA Gates belts, but then realized the Yanmar belts are Metric (13mm?) and ordered one of those online. It made a huge difference in how the belt fits the water pump pulley.

Also, make sure the water pump pulley is not pitted with surface rust. Our engine sat for a while and the rough surface caused dusting until we sanded it smooth.

I run an Ample Power 120 which is set to 100 with the stock v-belt set-up. This is marginally successful, but I too would go sperantine if I had the spare cash.

Matt

[NYSail]

Twist at the heat exchanger and Slide the hose deeper......

[hlev00]

Originally Posted by amaka101

Hi,
I have a 4jh5e & I was wondering if anyone could let me know if this system would accept a 120A Bosch alternator.
thanks

It looks like the foot mount is the first challenge or problem with Bosch.

The challenge on the Balmar series 60 is that it is 5.3” diameter and the stock Hitachi is 4.6”. This wouldn’t be a problem except the position of the water pump results in almost zero variability in the belt size to let the alternator swing out further. Thus the extremely tight fit.

Is yours still the Hitachi rebranded or the newer Valero that I understand Yanmar is shipping on new engines.

[amaka101]

I just downloaded the Manual for the 4jh5e & found that it doesn't actually state an alternator as such.
It says AC generator 12V-120 A. Is this simply another term for the alternator ?