Rotor Magnets no good?

Hi folks,
my 1983 KZ750 L3 is not charging the battery. Charged battery indicates 12.5 volts with no load. With the engine running at 3000 - 4000 rpm's I only get 12.5 volts at the battery.
I have checked the stator voltage with engine running and only get 25 to 26 volts coming from either pair of the three yellow wires. I have a spare engine so I changed over the stator and get about the same voltage 25.8 volts with engine running. I know I should see about 50 volts from these wires with engine running. In your opinion, does this low voltage indicate that the rotor magnets may not have full magnetism? Is there a way I can check the rotor?
Thanks for your help.
Grant.

This applies to the Z1's,Kz900's,Kz1000's and Kz1100's but might work for your bike:

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.

MFolks,
thanks for the great advice and instructions. Today, we (Alex my son and I) changed out the rotor and now we have 50+ volts AC coming from the three yellow wires from the stator. Put it all back together and now we get 14+ volts to the battery at ~5000 RPM's. We shall see whether the battery can still hold a charge over the next couple of days. Again, thanks for your help.
Grant.

Happy I could be of help!

Here's some more items that can be of use:
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Ignition Coil Primary And Secondary Wiring

Ignition coils on the 80’s Kz1000,Kz1100’s and Gpz1100’s are wired the same, that is as you sit on the bike, the LEFT ignition coil primary(small wires) are two wires, RED and BLACK. The secondary (or sparkplug wires) got to #1 and #4 sparkplugs.

For the RIGHT ignition coil, the primary wires, again are two wires, RED and GREEN, with the secondary going to #2 and #3.

The RED wire gets it’s voltage from the run/stop switch on the right handlebar switch pod.

The BLACK and GREEN wires connect to the IC Igniter(if the bike has the Kawasaki supplied electronic ignition) it actually gives the coils their grounds to fire the sparkplugs.

The primary(small wires) side of the coils will read between 1.8 to 3.0 ohms.

The secondary(sparkplug wire ports) will read between 10.4K to 15.6K ohms.
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Ohm Checking Pickup(Pulsing) Coils

The pickup coils on the Kawasaki’s with the factory supplied electronic ignition can sometimes fail or become intermittent due to heat and vibration.

1.Trace back from where the pick up coils are mounted,(under a right side CD sized cover) locate and disconnect a small 4 pin connector. Using a multi-meter set on OHMS and range of X 100 check between the BLUE and BLACK wires(#1 and #4 sparkplug wires) for between 360- 540 OHMS.

2.For #2 and #3 sparkplugs the wire colors will be YELLOW and RED, again 360-540 OHMS.

3.If the pickup coils are suspect of failing due to heat, they can be stressed using a hair dryer without the need of the engine running.

4.A replacement set of pickup coils might be obtained from a dealer who serviced the police Kawasaki’s.

5. If replacement pickup coils are not available, your next choice would be to order a Dyna “S” electronic ignition system from www.z1enterprises.com It replaces the IC igniter with a smaller module located where the mechanical ignition advancer was mounted.

6.Check the small 4 pin connector that the pickup coils connect to for corrosion/loose pins too.
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Over Running Starter Clutch Repair On the Older, Bigger 4’S

1. When preparing to repair the starter over running clutch have a few items on hand:

A. New alternator cover gasket.
B. New springs (3).
C. New spring caps (3).
D. New rollers (3).

2. If possible, put the motorcycle on the center stand and tilt to the right to reduce the oil volume in the alternator cover.

3. Place an oil catch pan under the left side of the engine to collect what small amount of oil that will escape when the alternator cover is removed.

4. Remove the foot shifter lever, left foot peg assembly and the sprocket cover.

5. Some Kawasaki’s have socket head cap screws(Allen type) and others may have fasteners with a Phillips type. If the latter is there, a # 3 bit seems to work the best for removal.

6. Remove the alternator cover and take care with the three wires coming from the alternator stator. These are the voltage supply wires for the motorcycle. Rest the cover on some newspaper or rags to prevent damage.

7. The magnetic Rotor or flywheel will probably require a removal bolt or puller. NOTE, SOME ENGINES HAVE LEFT HAND THREADS ON THE ROTOR!!

8. The over running clutch is bolted to the back of the rotor with three Allen head fasteners.

9. Separate the rotor from the over running clutch and inspect for damage in the springs, rollers, and spring caps. Replace any worn parts.

10. Re-assemble in reverse order taking care when re-installing the Alternator cover not to pinch any wires. If the cover will not re-install without force, check before any damage occurs.
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Starter Solenoid Checkout

Some simple steps to determine what is working and what's not:

1.Fully charge and test the battery(most bike shops can load test the battery, and then use a floating ball hydrometer to check specific gravity in the charged cells).

2.Clean all battery terminals of corrosion.

3.Tighten all starting related connections(Positive RED(+) battery terminal, Negative BLACK(-)terminal) and from the terminal to the engine case. All connections must be clean and tight.

4.Clean the cable from the starter solenoid to the starter motor.

5.Clean and check the "bullet connectors" going to the coil side of the starter solenoid.

6.Try again to start the bike.

7.If no luck, go to step #8

8.Wearing eye protection, bridge with pliers or a screwdriver the two heavy duty(large)terminals on the solenoid. If the bike cranks, your solenoid may be bad.

9. If the starter won’t turn over, one of several things has happened; The starter motor has seized due to brushes binding up, lack of lubrication in the bushings of the motor, the battery is weak , the engine has seized or it could be a combination of any of the above. Some websites for starter motor rebuild kits are:

A. www.mawonline.com/newsite/rick_s_motorsp...-starter_brushes.htm

B. www.cyclewareables.com/pages/street_star...kits/startmtrkit.htm


10.The dealer may want $$$ for a new solenoid, but take your old one along and visit the nearest riding lawn mower shop. They have solenoids for about $15 that with a little work will fit. Be aware that the new solenoid from the lawn mower shop may require a ground wire for it to work.

11. I’d recommend upgrading from the existing battery cables to at least 6 gauge welding cables.
They are available in two colors(RED and BLACK) have more flexibility due to being constructed with finer conductors, and will fit in tighter areas.

12. The welding cable is sold by the foot, so take careful measurements or bring your old cables along. Most battery shops might be able to supply the cable too, so call to find out. The battery shop should be able to crimp/swage on the end of the welding cable the terminal ends or lugs using either a dedicated crimping machine or a tool that looks like a bolt cutter that has special dies to terminate the cable.