Minor Balmar Rant

[Indolent58]

A few months ago I replaced the stock 80amp alternator on my Yanmar 4JH4-TE with a Balmar XT 250amp alternator and MC618 regulator. Notwithstanding the absurdly obsolete user interface of the MC618 the setup works well enough and is a major improvement over what I had before. But two things really got my attention and being a cranky white male I have decided to share.

1. Balmar decided that the best place for the positive output terminal was on the side of the alternator case rather than the back where it is typically located. If your alternator is located on the port side as mine is this puts the positive terminal perilously close to the engine block. Why do this? It’s frankly stupid and negligent. I have placed insulation between the terminal and engine block to prevent a catastrophic short if the tensioning arm gets loose somehow. When I have access to materials and tools I will get a longer tensioning arm and belt to move the alternator further away from the engine, but if the positive terminal was in a safer location this would be unnecessary.

2. Balmar high output alternators have 16 poles rather than the standard 12. If your diesel engine takes its tach input from the alternator rather than a flywheel pickup as mine does your tachometer will be incorrect unless it can be adjusted. As you might guess my Yanmar supplied tachometer is not adjustable. I was advised that in my situation I should get the Balmar 15-TSS Signal Stabilizer. When I installed it I couldn’t get any reading at all from the tach at all no matter how it was adjusted. After a bit of back and forth with Balmar technical support one of the reps said that the device was originally designed for the now discontinued Balmar AT series alternators and he didn’t think it would work with current XT alternators. So why do they still sell it? Whatever. The solution seems to be that I will have to buy a tach with an adjustment range compatible with the XT, but when I asked Balmar which tachs and/or what specs I should be looking for I was told that they really hadn’t looked into that and had no advice. Really?


OK that’s it, and while we’re at it get off my lawn.

[SailingHarmonie]

Doesn't the 4JH4-TE have standard a tach sensor that counts flywheel teeth? Some Yanmars do, and I am 98% sure this is one of them...

It does not need the alternator at all... If you just disconnected the existing tach and connected it to an output from the alternator regulator it will never work...

[Indolent58]

Originally Posted by SailingHarmonie

Doesn't the 4JH4-TE have standard a tach sensor that counts flywheel teeth? Some Yanmars do, and I am 98% sure this is one of them...

It does not need the alternator at all... If you just disconnected the existing tach and connected it to an output from the alternator regulator it will never work...

Yanmar changes things up from time to time and not all 4JH4-TEs are the same. The tach was connected to the tach out of my old alternator and I can’t find any evidence that my engine has a flywheel pickup. I’ve looked for it on the engine and in the parts catalog for my model with no success

[pjShap]

I also have a Yanmar 4JH4-TE. I don't know if I have the original tach, but my VDO tach that's part of the Yanmar instrument panel is adjustable. On the back of the tach there's a small button for calibration, centered horizontally and near the bottom vertically. I had to recalibrate after installing a Balmar serpentine belt kit- the pulley diameters changed from the stock v-belt setup. I can send you calibration instructions if you do have a programmable VDO tach.

[Indolent58]

Originally Posted by pjShap

I also have a Yanmar 4JH4-TE. I don't know if I have the original tach, but my VDO tach that's part of the Yanmar instrument panel is adjustable. On the back of the tach there's a small button for calibration, centered horizontally and near the bottom vertically. I had to recalibrate after installing a Balmar serpentine belt kit- the pulley diameters changed from the stock v-belt setup. I can send you calibration instructions if you do have a programmable VDO tach.

I think I’ve seen those instructions, but my tachometer neither has the button, nor an LCD engine hour display, both of which are needed to adjust it. Do you happen to know the model number?

[pjShap]

I don't know the VDO tach model, but it does have the LCD engine hour display. If I did the file attachment correctly, the attached YanmarVdoProgrammableTach.pdf has the instructions.