12V ETZ: Charging problems & fix

[Puffs]

On my bike, an '89 ETZ 251, I've had some charging issues, in that it didn't.

I normally ride with the headlight on, a H4 55/60W unit, and problems first became apparent by the engine cutting out. Switching the lights off made it run again, but getting closer to home it also cut out on the indicator light. When I came home, the battery was almost flat & measuring the voltage indicated it didn't charge, not at all. This had happened before, and then I had traced it back to a faulty connection inside the original mechanical voltage regulator.

Measuring on the regulator (see Fig. 6.3 in the Haynes manual), I had 14.3V from the rectifier, on pole D+, while pole 51 (which connects to the battery, un-fused) reads the much lower battery voltage. After I took off the regulator's cap, and sure enough, that same connection again had free play:

Poor connection in ETZ regulator.jpg (48.79 KiB) Viewed 13 times

Measuring while pushing the wire into the connection gives 14.3V, also on pole 51.

I had soldered this connection before, but I cannot solder it properly, as I cannot get it warm enough: the pole drains too much heat from my soldering iron. Last time I soldered it, it kept for the summer. Maybe if I take the regulator off the bike, shield parts & use a flame it could work, but I haven't done that. Shielding the rest properly from a flame seems difficult.

Instead, after isolating the battery, I wound some copper wire around the coil end, and knotted that to the pole. Thereafter covered the lot as good as I could with fresh solder. It does make an electrical connection, but it hasn't flowed well.

Poor connection in ETZ regulator - re-soldered.jpg (39.6 KiB) Viewed 13 times

Anyway, I think the real problem is not in the soldering, but rather that the heavy coil is being fixated by that soldered connection. And that the coil vibrates. So I fixated the coil, at the other side, with some epoxy clay:

Poor connection in ETZ regulator - coil fixate.jpg (29.32 KiB) Viewed 13 times

Hope it keeps a bit longer now.

It's obviously an age problem, but I like this mechanical regulator. Hopefully this is of use to someone, once.

[DAVID THOMPSON]

problems like this can be caused by bad solder also

[Puffs]

True, but also the original soldering had come undone due to vibrations. After quite a while though, but it did fail.

I have 2 electric soldering irons, a 30W one with a narrow tip (for electronics) and a 100W one with a slightly wider tip. Both are insufficient. You can see from the colour of that bottom wire that I tried to heat it up long enough: the isolating varnish has become lighter. Even that 100W just doesn't get it warm enough.

For something like this, you can solder it the plumbers way, with a flame/torch. Problem is that you will then burn what's behind, unless you shield it, but shielding the rest properly from a flame seems difficult.

If it fails again, the other thing I can try is soldering it with an old-fashioned soldering iron. I mean the heavy copper head on a stick, which you first heat-up properly with a torch, and then use for soldering. Come to think of it, maybe that's what they used for the original assembly. Still have a couple of those.

[Puffs]

Maybe I attached the regulator the wrong way, to directly & to 'hard' to the frame, and thereby caused the vibration failure myself. I do not have any special parts for that attachment, and on the left side it is in rubber, but the right side is just screwed. I have no idea how it was originally.

Does anyone have a picture showing the original mounting method? This does not really show it.

Bild 70, Elektrik unter der Sitzbank.jpg (32.31 KiB) Viewed 13 times

[dave47]

It definitely shouldnt be rigidly mounted. I replaced mine with an electronic one years ago, but as far as I remember it was fixed on the right side with a rubber "shock absorber" similar to that at the bottom of the rectifier. At the left side it was in a foam rubber sleeve.
Edit: It is part no. 30-34.037 Fastening rubber for regulator cut-out.

[Puffs]

Thanks for putting me on track Dave!

While Guesi indicates that part for mounting the flasher relay, I can see how that would work. And I now also find his picture:

It's gizmo #17 & #18.

I resurrected this bike in the winter '17-'18 and indeed the remnants of #18 might have been there, but perished. That side now is in rubber, that's OK, but instead of #17 it has a bolt to the lip on the frame - to be updated.

[parrbd]

Yes that part rotted away on my ETZ250. I squirted a bunch of silicone around that end an let it set. So far, so good. Regulator still works and keeps the original 1985 battery charged.

[Puffs]

Yes, silicone would work. On the left side mine is in an old 'O'-ring, you know the big ones you get when you replace the oil filter in your car. On the right side I f'ed up.

I gave it a new battery, a little over a year ago, as the previous one didn't hold charge anymore, after being dormant for a decade or so. Not sure if that was 'original' - maybe. As I need a charged battery for my (original) ignition, I bought a new battery. Btw, 35 years for a lead-acid battery sounds quite phenomenal!

In many cases the battery is not provided by the manufacturer; the manufacturer ships the bike without fluids & battery, and the dealer who sells the bike to the customer fills it with fluids & places a battery. Not sure what MZ did at the time, exporting bikes to Oz, but yours might be an Australian battery.

[parrbd]

Yes the Battery life has amazed me. I have changed quite a few batteries in other bikes over the same period. The battery supplied with the ETZ when I bought it was a Yuasa standard lead acid battery. Twenty plus years ago I came out to ride it to work but the battery was flat. So I pushed it into the back of the shed. There it stayed until a few years ago. When I pulled it out to recommission it I noticed that the headlight and ignition had been left on all that time. The battery was about quarter full. I topped it up with tap water and put it on the charger. It held charge, the bike started and has been working fine ever since. I know it does not make sense.

[Puffs]

Two seasons back I put a small AGM-type battery, that's the sealed type, with lower capacity than prescribed, and that works fine - as long as the thing charges. No charge --> battery drains.

For the record, here's how the left side of the regulator is/was attached, seen from above:

LH regulator, from above.jpg (34.28 KiB) Viewed 13 times

A large 'O'-ring runs through those holes, on the top side of the regulator base, and is knotted together on top with a zip tie. From below it looks like this:

LH regulator.jpg (22.25 KiB) Viewed 13 times

And on the RH side, as follows:

RH regulator + flasher relay.jpg (31.69 KiB) Viewed 13 times

I replaced the bolt I had before (see the lower RH corner in download/file.php?id=5325&mode=view ) by a little zip tie, and ran the 'O'-ring (which I use to flexibly hang the flasher relay) between the regulator base & the frame lug. Previously that side was hard.

Now the regulator is quite flexibly mounted. If I still get problems, I'll post them - but I suspect this solves it.