charging problems

hi guys i need some help to figure out a charging issue on my 83 kz750 l3
the problem is that it doesnt charge the battery i have checked every thing i can think of the bike only puts 13.8 volts out

Go to www.electrosport.com and find their troubleshooting page, it should help you figure out whats going on.

I had a similar problem with my KZ650-C1. The problem was a bad diode in the rectifier; replaced the rectifier - problem solved. Unlike mine, your bike may have a combination regulator/rectifier. The Kawasaki Service Manual should have a section that describes how to test it. Run those tests and you should know for sure if that is the problem. Here's where I bought what I needed:

www.oregonmotorcycleparts.com/Products.html

Something I found in my records:

Kawasaki KZ650 Charging system information

Below are the systems used on the 650s. As you can see there are basically 3 different systems used, 2 of which are 3phase which use 3 wires and the other is single phase which used 2 wires. I would think that you could use the stator you have purchased but you will certainly have to change the regulator / recitifier to make it work correctly. You will need to get the unit(s) that are used by the machines that the stator came from.

First gen. uses 3 wires
1977 B1 standard...3phase excited field
1977 C1 custom.....3phase excited field

Second gen. uses 2 wires
1978 B2 standard...1phase permanent mag
1978 C2 custom.....1phase permanent mag
1978 D1 sr.........1phase permanent mag
1979 B3 standard...1phase permanent mag
1979 C3 custom.....1phase permanent mag
1979 D2 sr.........1phase permanent mag
1980 E1 LTD........1phase permanent mag
1980 F1 custom.....1phase permanent mag
1980 B4 standard...1phase permanent mag
1980 C4 custom.....1phase permanent mag
1980 D3 sr.........1phase permanent mag

Third gen. uses 3 wires
1981 D4 sr..............3phase permanent mag
1981 F2 ................3phase permanent mag
1982 F3 ................3phase permanent mag
1983 F4 ................3phase permanent mag
1981 H1 csr.............3phase permanent mag
1982 H2 csr.............3phase permanent mag
1983 H3 csr.............3phase permanent mag up to KZ650DE052650

Fourth gen.
1983 H3 csr.............New type 3phase permanent mag starting at KZ650DE052651

krazinite2003 wrote: hi guys i need some help to figure out a charging issue on my 83 kz750 l3
the problem is that it doesnt charge the battery i have checked every thing i can think of the bike only puts 13.8 volts out

the bike only puts 13.8 volts out -- at what rpm?

Good Fortune!

Check output of each pair of the three yellow stator wires. Voltage will be 56 ACv or so. Make sure the wiring has No resistance, poor connection from stator to Regulator/ Rectifier. Also from R/R to Battery and Ground. Sounds as though you have a poor connection, resistance causing voltage drop.

i have tryed every thing you guys have mentioned even got a new battery ,and the 13.8 v at at all ranges of rpm i even tested the other bike i got and same voltage i have all the testing procedures listed in two books that i have chilton an haynes
ive swapped parts onto the bike that i got sitting around this is why im confused every thing has tested ok

Is the charging system voltage output being measured between the battery posts?

Voltage at 4,000 rpm should be higher than voltage at idle rpm.

If voltage measurement always remains the same, and doesn't change between idle and 4,000 rpm, there's likely a faulty charging system component, or faulty wiring, or a faulty connector.

Good Fortune!

If needed, here's a link to the wiring diagram in KZr's FILEBASE.

Click > www.kzrider.com/filebase/doc_download/316-z750l3

Good Fortune!

OK, somewhat confused here... :S

You have 13.8Vdc output being measured where, at the battery terminals...?
If so, this is more than enough for charging the battery @ idle for example and does indicate charging circuit operations. Granted @ 4000rpm should be measuring ~ 14.5Vdc....

It wouldn't be an open in a rectification phase for you'd measure 1/3 less DC voltage.
Shorted diode would most likely blow fuses.

You mentioned tested on other bike so assuming same model (KZ750)... At higher rpms, are you seeing an increase to ~ 14.5Vdc on this bike or receiving the same results...?

1) With a charged battery, measure the Vdc at the battery terminals and leave turned off for a day or two.
2) Measure the battery once again, how much Vdc loss are you know measuring...?

If you find more than a 1 volt drop than you have a short somewhere in your harness/electrical wiring.
Translation, your charging circuit is operational it's just constantly draining the battery when turned off. Possibly the igniter has a partial short, try swapping the igniter as well (only if same model)...?

As mentioned by others, disconnect & clean all charging circuit connectors.
Insure all grounds to frame and engine are clean/non oxidized/no painted surface etc...
Insure all terminal connections are not frayed/oxidized/clean...

Maybe this will be different than your other manuals... Out for OEM manual....

Follow link and download...
OEM KZ750 Manual... FREE!

My KZ650-C1 has a 3-phase charging system with a separate rectifier and voltage regulator. The stock rectifier contained 6 silicon diodes. When my original rectifier had one diode fail the battery was getting about 12 volts at idle and 12.7 volts at 4,000 rpm. This was not enough to keep the battery charged; it would very slowly run down. The rectifier diagnostic test described in the FSM was easy to perform. It involved taking 12 measurements at the rectifier using an ohmmeter to determine if the diodes were functioning properly. These measurements revealed one defective diode that was permitting current to flow in both directions. Having the rectifier separate from the regulator made this problem very easy to diagnose and fix. Ed

On your model you have a 6 wire R/R. It has a Brown wire, which is the Voltage sense for the charging. If you Briefly un-plug it from the R/R connector, with the bike running you should see as much as 18 DCv at Battery. Running the motor just for this quick test will tell you if the charging circuits will supply full output to the battery. Then I would try another R/R assembly, as the set point may be higher.
13.8 DCv should keep your battery charged, but as OMR posted the system is set up to make 14+.
I have 13.8 on my Concours, Voltmeter installed on dash, visible while riding. It uses the same Battery as my KZ. It will show 14.2 just after starting, then drop to 13.8 as the battery recovers the starting amperage. This has an Alternator that Fielded by an internal regulator.
If your battery is going flat. Take your volt meter, and place one lead to the frame, the other to the battery cable in series with the battery. This will show if there is any draw from the electrical when the bike is off.