TOPIC:

I’m looking for a technician in upstate NY that could help me with a charging issue on my 77 KZ650. There aren’t too many old Kawasaki techs left. The bike is running off the battery so most likely an issue with the stator, regulator, or rectifier or the wiring  between them. Any leads would be appreciated.
 

All you need is an auto electrician, doesn't need to be motorcycle specific,  a few simple tests will tell you what not working...

F64, a member here is excellent at helping and diagnostics procedures. With his help, your time, and a nominal expense for a cheap multimeter I’m sure he can help. Bonus you will start to learn your bike charging system. 

Hehe thanks Mikaw,
I think I might just be really stubborn.

Digger,
Do you have a multimeter?

You need a multimeter with a diode checker for the rectifier/regulator.

Thanks for the offer of help. I could use it. I have a multimeter. The bike’s wiring was a cobbled mess when I got it. It’s possible the charging system wiring is incorrect. Probably should verify correct wiring before doing much testing. What are your thoughts ?

The 1977 Kz650 has a charging system different to all other Kz650's.  It's a little more complex, but the upside is that when it's working properly it's a superior system.

The way to confirm it is for sure a 1977 Kz650 charging system is to look at the left side of the engine.  The alternator cover (big round cover) will have three screws in a triangle pattern.

For reference, here is a stripped down 1977 Kz650 diagram.  
kzrider.com/forum/4-electrical/172746-19...ght?start=444#805991

And here is a simplified diagram of one using an aftermarket combo reg/rec unit: 
kzrider.com/forum/4-electrical/172746-19...ght?start=420#791271

A 3-phase, hi-power (50Amp) rectifier can be found on ebay for dirt cheap and have been reported to work nicely, if that part of your system is failed.

F64 can guide you through the troubleshooting. 

Note: Connecting the brown wire to the green wire at the regulator (with regulator disconnected) will put full voltage on the field coil for stator and rectifier output testing (this is actually one of the tests in the FSM).

If you have a 650B, here is a link to a downloadable pdf copy of the factory service manual. 
www.kzrider.com/modules/ServiceManuals/K...Service%20Manual.pdf

If you have a 650C, most of the B manual will apply, but the C had different brakes and wheels, and there may be some other differences as well. You can easily tell which you have by looking at the frame number. It will start with either KZ650B or KZ650C.

In a couple days I’ll have the bike back on the lift in the heated portion of my garage. I’ll see if I can verify that the charging system wiring is correct and then I’ll pick your brain, if that’s okay.

Hey 77,
Did you get the bike on the lift?

Just got it on the lift late today. I’ll try to double check the wiring tomorrow.

I'll put my brain on later tonight and look at the schematic.
The first tests will just be added to this post.

ok
Make sure your battery has been charged.
Grab your voltmeter.
Key on, Ignition on, Bike running

meter on DC V
Black probe on the center of the negative battery post (post will be the metal part of the battery. Not the part of the cable that attaches to the battery)
Red probe on the positive battery post
What is the voltage ?

Raise your rpm to 2000rpm
what is the voltage

Turn on your high beam
what is your voltage?

Raise the rpm to 3500rpm
what is your voltage?

Turn off the bike