TOPIC:

My 1978 KZ1000A2 is alive and running.
I'm looking for ways to spruce up the aging electricals. It barely passes the voltage tests in the clymer manual it hits 14.0 volts at 4000rpm.

For the '79 models theres a test for stator voltage ( >50 volts for each leg of the stator)

There's no spec listed for this on my '78. I checked it anyway and am getting a mighty 20.2 volts. All resistance tests on the stator are normal. I know stators are all about Power ouput (P=V*I), but is 20 volts enough, especially since I want(need) brighter lights, heated grips, blender, microwave etc.

I still have the old separate reg/rect and will get a combo unit for reliability.

ideas?

thanks...Sam

Please specify:

Is the voltage reading an AC voltage across the "AC" (yellow) wires when they are unconnected to anything?

Understand, when the AC wires are connected into the system, the SCR diodes will clamp the voltage of the AC lines to a couple of volts above the battery voltage with respect to ground. It will be a DC voltage with a small amount of AC ripple on it. The battery acts like a giant filter capacitor after the rectifier output.

Sam... you got 14VDC at the battery at 4K rpm? Is that correct? That ain't bad and will keep the battery charged fine. Its on the low side but still OK.

How did you get one AC voltage of 20.2? When you have three yellow wires coming off your stator, you need to put a meter hot probe on one and neg probe on another. With the bike running, gun the engine to 4K rpm and get a reading. In other words the yellow wires are A, B and C... Measure A & B, then A & C then B & C. You need THREE measurements taken at the same 4K rpm. If you did the readings at idle, they will be low. The stator AC output generally doesn't degrade with age. What happens is that the plastic covered windings will heat over the years and the plastic coating will melt. When two of the three windings touch, they short. NO POWER. You can buy a new stator if this happens but you can get a stator rewound by a car place that does rewinds on alternators.

If you are not comfy with the stator, buy a new one if you like. I think Jeff at z1enterprises.com sells both a combo reg/rec and stator made by Rick's Electrics and this stuff is the good stuff.

I will also point out that the most common stator problem area are the three wires coming off the stator and not the stator itself. These wires were originally clad in a fabric sheathing cover. This cover is often worn away and the wires beneath cracked and/or spliced. I ALWAYS remove these wires and keep only the very ends with the pins that go into the blue connector. I splice on NEW wire and run it down to the stator and solder it in. I cover the three AC wires with a bunch of electrical tape. You will find that the green wire to the neutral switch and blue to the oil pressure sensor are also going to be brittle and cracked from their proximity to the engine cases.

Samwell wrote:

My 1978 KZ1000A2 is alive and running.
I'm looking for ways to spruce up the aging electricals. It barely passes the voltage tests in the clymer manual it hits 14.0 volts at 4000rpm.

That barely passes? Hmmm.... some time back I worked on the design of a charge control IC for a car's charging system for Chrysler and the spec was 14V +/-0.5V, so the spec is pretty sloppy on the system voltage the regulator holds the battery to. IMHO, 14V is just right for a lead acid "12V" battery at average temperatures so I think your regulator is OK.

For BH and WG:

the 20.2 volts is AC and its measured across each of the yellow wires - all three readings were very similar. This was done with that stator unplugged from the panel and the engine at 4000rpm so it should be whatever the stator can generate.

When I say barely passes, there's also a test for the regulator. Unplug it from the system and measure your voltage. well, with or without the regulator it never seems to get above 14 volts.


I guess the answer its ceratinly reasonable voltage. I'll keep the stator as is, but I think I'll get the combo reg/rect and some new wires from stator to panel for piece of mind.

thanks guys!

The stator voltages seem low to me. I would expect about double that AC voltage on each pair if memory serves. If they are all the same, that seems odd. Only way I can think that they would all be the same and low is if the stator got demagnetized. If someone had popped it with a hammer, for instance or something along those lines.

That's way low voltage from the stator. Have you been running a bad battery for an extended period of time?

larrycavan wrote:

That's way low voltage from the stator. Have you been running a bad battery for an extended period of time?

Well, no I haven't. I've only put about 200km on the machine. I don't know what the po's did. The battery isn't toast, but not great either. I'm considering a replacement, mostly to get a maintenance free one.

What were you thinking about?

S

wiredgeorge wrote:

The stator voltages seem low to me. I would expect about double that AC voltage on each pair if memory serves. If they are all the same, that seems odd. Only way I can think that they would all be the same and low is if the stator got demagnetized. If someone had popped it with a hammer, for instance or something along those lines.

Well, I was pretty careful when handling the stator, but I'm not a professional mechanic and may have done something dumb accidentally. I should've tested the output before I disassembled and rebuilt it. Live and learn I guess.

thanks for the advice...S

If you attempt to remove the stator from the cover, you have to pop the cover to get the stator to drop out. This popping can DEMAGNETIZE the stator windings. If you heat the cover with the stator inside, this can DEMAGNETIZE the windings. I am not saying YOU did this, I am saying this is how it can happen. With your AC voltage output and the fact that the regulator is working (probably OK), it may have happened a long time ago but didn't get resolved. Look for a stator cover on eBay as many have the stators still in them. I have bought several this way and they are usually good. I know that stators can be demagnetized because I have done it by both the rapping and heating methods hehe...

wiredgeorge wrote:

If you attempt to remove the stator from the cover, you have to pop the cover to get the stator to drop out. This popping can DEMAGNETIZE the stator windings. If you heat the cover with the stator inside, this can DEMAGNETIZE the windings. I am not saying YOU did this, I am saying this is how it can happen. With your AC voltage output and the fact that the regulator is working (probably OK), it may have happened a long time ago but didn't get resolved. Look for a stator cover on eBay as many have the stators still in them. I have bought several this way and they are usually good. I know that stators can be demagnetized because I have done it by both the rapping and heating methods hehe...

Well I do love my rubber mallet. You can really wail on things and not mar surfaces. (Not that I'm admitting to anything! ) On the plus side I hooked my multimeter in series with the battery. At idle I have -1amp but at 3500rpm I have +4 amps that have nothing to do but charge my battery (or power an extra light). On the down side there's a current leak in my rectifier somewhere. When I have the multimeter in series, there's no current drain from the frame ground, but there's about 100 milliamps drawn when the rectifier ground is connected in series. I've read somewhere that this means the rectifier is failing. Oh well, more to do.

Thanks...Sam

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