KZ-750 Charging

Ah yes the plot thickens
I am using a Kawasaki Factory service manual from 79-83
Could it be I'm missing the whole point because I have and older bike with the newer manual.
Capt. America- explain what you meant about the older system
are there any other bench testing I can do. I am using a good quality Fluke Digital V/O meter

Thanks

OLD:
The 76 and 77 twins came with a huge stator, a field coil in the center, a sperate rectifier, and a sperate voltage regulator that simply turns the field coil off and on to produce a magnetic field(it's only function). They have a smaller/lighter flywheel with no magnets in it. Just a note but, the 76/77 flywheel bolt only torques to 51 to 58 ft lbs if you ever need to remove it. This systems stator has (3 yellow wires) out, and 2 for the field coil on our twins.
NEW:
The 79 through 83 had a permanent magnet on the flywheel and a newer smaller stator that sits on the inside of the flywheel when the alternator casing is on the bike. They came with a combo regulator/rectifier. This system only has (2 yellow wires) out from the stator.

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I simply like the newer system because it isn't reliant upon a field coil and voltage regulator to turn it(the magnetic field) off/on to produce and regulate output. Also the newer systems stator's are much much cheaper to replace, if you're ever forced to buy a new one. The bike will also run as long as you don't have a shorted battery.

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I hope this helps. I just used the resistance reading checks I posted.

I found the stator I got with this 77 to be bad simply with the ohm readings I posted for you. I had 2 connections that were in spec, and one that was reading off the charts. I replaced it for 60 bucks from a scrapper with one that was in specs and now have a constant 14.5 at the battery at anything above 1,100 rpm.

Since I don't have a bench power supply that would produce above 16 volts DC to test the voltage regulator on the bench. I just put some alligator clips on my cheap digital voltmeter and taped it to my tank and went for a short ride(removable paint tape, don't get all duct tape crazy. LOL.) I could see the voltage momentarily drop off as the regulator clipped in and out to prevent much higher than 14.5 It's a very quick clip so you really have to watch for it, but I live on a gravel road so no traffic worries for me. At least I know it's working, even if I did look funny. Plus I could see I was getting a good 14.5 volts current from the stator.

My field coil ohm readings were within specs as well. My rectifier bench tested out within specs as well, both are working fine so far.

If you're loosing battery voltage as you ride and you know it to be a good battery. I'd suspect the stator or field coil, or their ancient connectors. If it was the voltage regulator not kicking off you'd probably be blowing lights head/tail since the system isn't really regulated. Yet if the regulator is not turning on either, you would get no current from the stator since the field coil won't be activated. I wouldn't use your good meter, but a 7 or 8 dollar digital one is well worth pasting on while you go for a ride.

Oh, on you're earlier post, yes we run a wet stator and it is open to engine oil. IF you tipped your bike right over on it's left you could just drain your oil that way.. snicker. :silly:

Wishing you luck!

Guess I should have smelled a rat when the book stated to check the armature by disconnecting the yellow leads down under the shifter cover . I had no such connector and also more than 3 yellow wires leaving the armature and heading to the rectifier and regulator. They are separate components on my bike.

loudhvx wrote:

Capt America wrote:

... Just a note, but never disconnect the voltage regulator with the key on, on these old girls or you can fry it.
...

Never heard that before. Why would that fry the regulator?

So I've been going over it in my little brain pan. I might have a reason for Kawasakis warning about the voltage regulator.

Are older Kawasaki points style voltage regulators polarized like the others I've encountered? Is it possible, that it is a warning so you don't change the polarity on the regulator?

I've had to set the polarity on replacement points style regulators for Harley's and a couple other things. Perhaps the manufacturer set the polarity on them at the factory. They may just want to insure you don't change it by unplugging it with power on, and negate or reverse the polarity?

If they are polarized and you change/neutralize the polarity on it, the unit would become useless. Especially if they need it set by a method, that can't be replicated using the normal garage procedure.

Capt America wrote:

loudhvx wrote:

Capt America wrote:

... Just a note, but never disconnect the voltage regulator with the key on, on these old girls or you can fry it.
...

Never heard that before. Why would that fry the regulator?

So I've been going over it in my little brain pan. I might have a reason for Kawasakis warning about the voltage regulator.

Are older Kawasaki points style voltage regulators polarized like the others I've encountered? Is it possible, that it is a warning so you don't change the polarity on the regulator?

I've had to set the polarity on replacement points style regulators for Harley's and a couple other things. Perhaps the manufacturer set the polarity on them at the factory. They may just want to insure you don't change it by unplugging it with power on, and negate or reverse the polarity?

If they are polarized and you change/neutralize the polarity on it, the unit would become useless. Especially if they need it set by a method, that can't be replicated using the normal garage procedure.

Yes, under certain circumstances if you accidently swapped some wires you may get a brief short. It would also act as a buzzer in some scenarios. But you would only really risk blowing a fuse. Luckily they color coded the reg with a sticker. They really should have used a 3-prong plug where there could be no mixup, though.

Here's a diagram of the one I took apart when I was bored. This is off a 400, but they are almost the same charging system. I made a solid state one to replace the stock one, and it did smooth out the voltage on the battery.

I believe the old type has more overall power and is more versatile, but I agree it's overly complicated and harder to work with. Also, I like the newer ones because you can eliminate the battery if you want.

I have a question, though, in regards to converting an old engine to the new type alternator. Is the end of the crank shaft the same for the two types of alternators?

I know on the KZ 650 people have converted from the field-coil type to the magnet flywheel type.

I wanted to do this on a 400, but the covers are not interchangeable like they are on the 650. But I wondered about the ends of the cranks too.

Any word on if they are the same?

Here's the 76 kz400 system.

Here's the one I made in case you are inclined to build stuff like this.

I gutted out the old one.

Then I built the new one in a way that would fit the original box.

I had room to spare as it turns out.

And here it is complete.

loudhvx wrote:

I have a question, though, in regards to converting an old engine to the new type alternator. Is the end of the crank shaft the same for the two types of alternators?

I know on the KZ 650 people have converted from the field-coil type to the magnet flywheel type.

I wanted to do this on a 400, but the covers are not interchangeable like they are on the 650. But I wondered about the ends of the cranks too.

Any word on if they are the same?
[/quote]

I wish I was able to help, but I just don't know about the 400. I've only ever had one and it was years and years ago, like in 1985ish. I've had several 440's and I found most of the parts from the 400 to be interchangeable with the 440's.. IF memory serves me, I believe the 440 motor would also go into the 400 frame.

I DO KNOW, it isn't possible to do on the 750 twin models.. at least it isn't possible to put the newer perm magnet flywheels on the 77 motor. I imagine the 76 would be the same. I suppose a machinist could pull it off with an insert for the flywheel or something, and drilling out and re-threading the crank end to take the larger/stronger bolt.

I have the flywheels from a 80,83, and a 79, 81 or 82 I forget which. I'd have to dig for the old ownership... anyway I have 3, 750 perm magnet flywheels and they are all the same.
The tapper on the 77 shaft is smaller, with a smaller weaker bolt and will not except them. All the engine casings are swap able on these 750s, the dowel pins in the exact same place etc, but the flywheels are not interchangeable. Which sucks since the alternator casing is.

I was told someone did it with a 79 flywheel put onto a 76.77. I'd want to see it to believe it though.

Just so ya don't think I'm talking out of my pooter. Here are some pics of my 83 belt drive back together and humping down the roads, now sporting a 77 motor with the older style alternator, and trimmed down/modified 77 harness.


My old frankenstien girl.


Just above my belt you can see the old rectifier at the side of my battery box.


As you can see I had to modify my belt/sprocket cover a bit to accept the older alternator.. The offset is quite dramatic between the two alternators. I could have just removed the small metal tab and one grommet from the alternator cover and I wouldn't of had to do anything to the cover, but with 5 wires I figured 2 grommets was a good idea. Oh well casing is an easy fix if I ever go back to one of my newer motors and alternator.


From this side you can see I have the 83 clutch casing which sports a mechanical pull for the clutch and is needed to run the belt drive.

Thanks very much for your diagrams and pics, Not sure if I could pull it off but in the future if I need to I'll attempt to build one of your regulators. I'm not sure if his 76 we've been talking about is the same as the 77 I got, but mine had a slightly different regulator, though having a removeable lid I'm thinking it is still points style.. another poor pic, but this is the regulator I have.

Thanks C-A, I suspected the flywheels were not interchangeable. Thanks for the confirmation.