Strange Issue With Ignition Switch 78 KZ1000A

My understanding of the charging system has the three yellow wires supplying the A.C. to the rectifier/regulator which then converts the A.C. to D.C. running the bikes electrical system.

Alternator Testing For the Older 4’s(Z1’s,Kz 900’s, Kz1000’s,Kz1100’s and GPz1100’s).

To check to see if the alternator is working you need to follow these simple steps:

1. Fully charge the battery as this will be the power source during this test.

2. Disconnect the Regulator/Rectifier at the plug that has the six wires in it.

3. Start the engine and let it warm to operating temperature.

4. If you're worried about overheating, position a large fan for cooling the engine.

5. After the engine has reached operating temperature, have a helper assist you, and using a multi-meter, read the output at the three yellow wires (or the alternator output wires)at the disconnected connector.

6. Raise the engine speed to 4000 rpm, and see what the three YELLOW wire combinations(or any alternator output wires) are(1-3, 2-3 & 1-2). The output will be around 50 Volts A.C.(Alternating Current). BE CAREFUL, AS THERE IS A SHOCK HAZARD HERE!!

7. If any of the combinations are low or non-existent, the stator(wire windings) are bad and must be replaced.
Some of the older Z1’s and KZ900’s were reported to be phase sensitive, so check the wire colors carefully.

8. Using an OHMETER, Check the three wire combinations again, looking for a reading of 0.36 - 0.54 OHMS. If the readings are above or below, the stator may be bad and need replacement. Also check from any of the three YELLOW wires to ground, this will show if arcing took place.

9. Before ordering a new stator, check the connections from the stator as there are electrical "Bullet" connectors that may be damaged or dirty.
Inspect the wiring for signs of shorting or overheating too. www.z1enterprises.com sells replacement rubber grommets for the alternator output wiring, they get hard and could leak oil after a while.

10. Check the wiring coming out of the grommet as there have been situations where the wires were damaged causing a short(I.E. twisted together with insulation damage).

11. The sprocket cover will have to be removed to access the electrical connectors coming from the alternator, the left foot peg assembly and shifting lever will have to come off also.


Alternator Stator Replacement On the Older 4’s
Source for replacement Stators

A. www.electrosport.com (They have a trouble shooting page)
B. www.customrewind.com
C. www.rmstator.com
D. www.ricksmotorsportselectrics.com
E. www.regulatorrectifier.com

1. If by testing either by checking the output voltage from the stator or by using and ohmmeter for resistance and the stator is determined to be bad, replacing the stator is not a difficult job.

2. The motorcycle owner should have on hand a replacement alternator gasket as it will tear on removal and leak if reused.

3. Put the bike on the center stand if possible and lean it to the right to minimize the oil volume that could come out when the alternator cover is removed.

4. Have selection of Metric wrenches and sockets along with Metric Allen keys to be able to accomplish this repair. ¼" and 3/8" ratchets and extensions may be needed along with Allen bits.

5. Remove the gear shift lever, the sprocket cover and possibly the left foot peg assembly.

6. A catch pan for what little oil will be lost should be positioned under the alternator on the left side. Newspapers will soak up any oil lost or some kitty litter will do as an absorbent.

7. Remove the alternator cover fasteners, some bikes use a socket head cap screw(Allen type) and others use the Phillips head type, the #3 screwdriver bit fits best for those. Use a small dish or can to collect the removed fasteners from the parts to prevent loss/damage.

8. The alternator stator is secured to the inside of the cover usually with three Allen headed bolts, Some bikes may have Torx style fasteners, Remove them and disconnect the three yellow wires that have bullet connectors on them from the bundled wires inside the sprocket cover.

9. If your bike has some color other than yellow for the alternator output wires, make note of what goes where as the older Kawasaki’s were phase sensitive in regard to the regulator/rectifiers.

10. When installing the replacement stator, clock or position the output wires and grommet so they fit into the small port under the alternator cover without being pinched or damaged.

11. Tighten the three Allen or Torx fasteners, securing the replacement stator to the cover. I like using the BLUE Loctite # 242 for hardware that can be removed with hand tools.

12. Remove the old gasket from the mating surfaces of the alternator cover and engine case by scraping with a piece of sharpened plastic like Lexan or Plexi-glass as these will not gouge the soft Aluminum Cases. Avoid using a metal gasket scraper for this.

13. Position the alternator cover, checking for pinched wiring and install the fasteners with a little silver anti-seize on the threads, tightening to the correct torque.

14. Connect up the output wires to the mating female bullet connectors and while you’re in there, check the routing of the wire bundle that runs through there.

15. Inspect for signs of heat damage to the wire insulation and vibration damage too.

16. The side stand switch, neutral switch, and oil pressure switch wiring are all bundled with the alternator output wiring running above and behind the engine output sprocket. This bundle runs in a channel as it goes up toward the various electrical connections.

17. The regulator/rectifier plug on the 80’s bikes usually has six wires in it:

A. One (1)WHITE with RED stripe, this is the bikes main power wire usually 12 gauge in size.

B. One(1) smaller Brown wire, probably 18 gauge or so, the voltage sense wire for the regulator/rectifier, helps keeping it from overcharging the battery.

C. One(1) BLACK with YELLOW stripe wire, part of the ground circuits, maybe 16 gauge in size.

D. Three(3) YELLOW wires, maybe 14 gauge in size, the alternator output wires going to the regulator/rectifier which converts the Alternating Current(A.C.) to Direct Current(D.C.) using rectification, producing the power to run the motorcycle and charge the battery.

18. Reinstall the sprocket cover, again checking for pinched wires before tightening. Install the shifter on it’s splined shaft checking for proper location, and the left side foot peg assembly.

19. Except for the minor oil spill and reluctant fasteners, it’s not a very difficult job to do.

Wow MFolks, thanks for all the information! Before reading your post, I went and checked the ylw/red wire with the voltage regulator disconnected. The wire does not have power when kicked as long as the voltage regulator is disconnected.

Some additional background - 2 or 3 years ago the battery wasn't charging properly. I tested everything and found that the voltage regulator was bad. After getting ripped off on flea-bay with a used one that didn't work, I bought a new aftermarket regulator. I carefully spliced and soldered the stock connector onto the new regulator, and the charging problem was fixed. Before I changed the regulator, the voltage at the battery would go lower as the RPM's increased...after the new regulator, it charges as it should.

Anyway, I think the stator is OK but I'm guessing the regulator has gone bad or there is a short somewhere. I will check the stator output again to be sure and also check for stator shorts. I don't remember the bike having this problem right after the new regulator was installed but maybe it did??

Anybody got a good used regulator for sale? This one has an external rectifier, not integrated as the newer ones do. Here's some pictures of the work, I'll have to double check to make sure the connections were made correctly.

Who did you buy the new regulator/rectifier from? I think this happened before to someone on the forum here recently. He found the new unit was wired internally wrong, putting voltage where it should'nt be.

MFolks wrote: Who did you buy the new regulator/rectifier from? I think this happened before to someone on the forum here recently. He found the new unit was wired internally wrong, putting voltage where it should'nt be.

I don't remember for sure, but I think it was Dennis Kirk. If I can find an old one to try, at least it will tell me if the regulator is the problem. I can't remember if I have an old one around or not....the 2 I had were bad and I cut one of them up to use the connector with the new regulator. There might still be another one somewhere.

Boy would I be interested to hear from the member that had a problem with his.

www.electrosport.com has a very good charging system troubleshooting page.

79MKII wrote: ...even with the key off, or the ignition switch completely disconnected for that matter, the motorcycle will start and run if I kickstart it...When I tested the ylw/red lead that powers the coils (and ignition), it switches on and off as normal with the key and / or kill switch. I then left the test light connected to the ylw/red wire and kicked the motor....the test light flickers even with the ignition off. Somehow, any time the engine is turning over, power is getting to the ylw/red wire that feeds the coils (comes out of harness under tank). Even with the ignition completely disconnected (power and both coil feeds) the symptoms are the same (I thought the power might be feeding back through the ignition). BUT...with the kill switch off, the power does NOT feed through when kicked....

Perhaps handlebar position is interacting with a frayed harness wire.

Would observe the test light while moving the handlebars through their range.

Good Fortune!

Received my "new" regulator today (used) and the problem is fixed. It was 100% the voltage regulator causing the issue. Very simple fix once you find it...but that's the tricky part.

Now I have to figure out if I just wired the new regulator incorrectly or did the $100+ new part go bad that quickly??

Kinda makes you wonder how many other bikes are out there that will start/run without the key being on? If it were me, I'd be contacting the supplier of the other regulator/rectifier and notify them of potential problems..

Now you have me wondering if the aftermarket regulator I got has gone bad too. My issue is a bit different though, when I shut mine off the engine does turn off but all the key "on" lights stay on even if you remove the key. After a cool down time of several minutes it will turn off if you put the key back in and turn it to "on" then "off". Guess I'll be looking at the reg now as a suspect too, thanks!

Wow....that's a strange one. I would've never guessed the regulator was to blame for my problem, so it's worth looking at. Just unplug it and see if the symptoms change.

79MKII wrote: Received my "new" regulator today (used) and the problem is fixed. It was 100% the voltage regulator causing the issue. Very simple fix once you find it...but that's the tricky part.

Now I have to figure out if I just wired the new regulator incorrectly or did the $100+ new part go bad that quickly??

It looks to me, in your photo, that you have the red output-wire on your reg/rec wired to the brown wire of the harness. I don't think that is correct, if that's the way you have it.

The brown wire, on the old regulator, was for the regulator to sense the system voltage. It should not be used as the wire that the output of the reg/rec is connected to.

Usually, on a 5-wire, 3-phase, reg/rec for permanent-magnet alternators, that red wire would go directly to the battery (with an optional fuse in that line).

If your bike originally had separate regulator and rectifier, the output of the combo reg/rec would go to the wire that was connected to the output of the rectifier. Actually, in your case, the entire reg/rec combo would get wired in place of the original rectifier (if your original rec and reg were separate).

The way you have it wired, anytime the motor turns over, the bike will have power even if the ignition switch is turned off. Also, the power will not be filtered by the battery, so when you switch the bike off, many short pulses of high voltage will likely hit the bikes electrical system until the motor actually stops turning. This can eventually damage electonic devices including the regulator.

EDIT: ignore this. My mistake. It is a regulator-only, not reg/rec combo. See below.

@LOUDHVX....thanks for the info. I will definitely be taking a closer look at how I wired it...can't remember for sure. Can't find paperwork that came with the regulator either (if there was any). WTF has happened to my memory? Seems I figured that out once but now I forget....

Not sure if it matters, but the new regulator is "regulator only", separate rectifier still in place.