Starts, Rides... Dies

So I've got my ride almost completely tuned for spring/summer. Been steadily plugging away against a multitude of random problems and I'm almost there. This morning I warmed her up and hit the highway for work. Even without having the carbs synced she's been screaming on the highway (making me a very happy man) but today I got off on my exit and the RPMs started to creep down. The more I gave the more they crept down. And then she just cut off. With cars speeding up on my rear. I wish I could explain how precarious the spot was that I broke down in. Crucially dangerous. The ignition was making the groaning dead battery sound but it's fully charged (or was). I waited for a break in traffic and pulled the ol' pop it into 1st push start and went as far as I could before the exact same thing happened again. Left her there and walked to work. Got off work. Walked back to the ride and she fired right up. Rolled equal distance to the house and it happened all over again. My lady came and picked me up and now my ride's hanging out in a SUPER sketchy section of industrial PDX. Is something sucking power off of the battery while I ride? I've tried to familiarize myself with most aspects of repair on this bike but I've yet to try my hand at any wiring issues. Does this sound familiar to anyone? Sorry for the novella of a post. I just wanna ride and know I'm good for at least a year or so!

Have your battery checked for problems first, then look at the charging system as these bike will quickly run down a battery with a bad alternator stator or regulator/rectifier.

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 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

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 may have to be removed to access the electrical connectors coming from the alternator and possibly the left foot peg, and shifting lever will have to come off.

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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.

Sounds like it's the charging system... runs off the battery for awhile - when you go back, it's (the battery) had time to "cool down", thus rechargeing it's self.
I'd get a friend to drive you down to pick it up... you can jump off a vehicle, but leave the vehicle & bike hooked up, but not running - give it time to "take a charge" off the donor. Ride it till it dies, and do it again ( have the chase vehicle follow you) if you have to... don't leave her out there tonight!

Possible fuel starvation?
Could test for blocked fuel cap vent by running with cap ajar.
Might also result from crud inside fuel tank, or dirty petcock pick-up screen (inside tank), or clogged in-line fuel filter.

Good Fortune!

Re; MFolks #19 point--Amen on the "reluctant fasteners" After 25 or 30 years, the bottom 3-4 bolts on the stator cover are welded into place.U will twist the head off at least one of them no matter how careful u r.Be prepared to drill out and retap at least one of the bolt holes.bj

A good aplication or either "Kroil" or "PB Blaster" on the fasteners makes a world of difference when doing removal.

If your lucky, the head will twist off, letting a vise grip to remove the fastener after the engine cover is removed.

When re-assembling, use some of the silver anti-seize on a few threads(just a thin coating will do).

I've seen a bad coil-coils cause this same issue before. In the lane way bike runs like a top, even revs like a top and goes around a few blocks without incident.. a ways down the highway though and the combined heat from constant current and the heat from the motor head and they just shut down.. allow a short cooling off period and the bike fires right back up and runs like a top again...

It will be worth your time checking all of your charging system like has been suggested by other, and also check the resistance on your coils and inspect them for hairline cracks, or a bad grounding. Even something as simple as a poor ground can cause excess heat when it comes to hydro.