77 KZ1000A1 Voltage Regulator

Mama Kaw went through many iterations of those old regulators due to overcharging.  Some that bench test good will still overcharge because the early ones did that and, when the later iterations of the the old style regulators fail they almost always overcharge, sometimes massively enough to blow light bulbs & burn points to a crisp.  Used ones will be a crap shoot.  They're a little delicate too, as they tend to fry themselves if the battery isn't fully charged to begin with.  They're really just battery maintainers that can't pass much current reliably.
On Z1's they were mounted in a hostile area behind the motor where cooling is a problem.  One of the best things Mama Kaw did for the old regulators was to move them to the side, away from heated air coming off the rear of motor.

We're making the transition to the SH775's on our Z1's as we go through seasonal rotation beginning this year.  A simple pigtail harness will make them plug n' play without butchering the OEM harness, making it simple to revert to original if desired.

Mikaw's  wiring diagram/schematic above is the clearest one we've seen.


Good Ridin'
slmjim

Thanks everyone. I managed to find a NOS OEM regulator for $225 + shipping. Searching last night turned up prices of $135 or so + shipping for SH775 units, with a lot of comments of fakes on eBay, so I decided to stick with the OEM. It's coming from Montana, so hopefully it will arrive quickly.

I've got a couple of clean and tested SH775 that I resell for $60 each.  These units are super robust so buying used is no risk.

Slmjim, the credit for the drawing goes to Nessism. I pulled it from one of his previous posts. I wanted it for my records

wrote:

Slmjim, the credit for the drawing goes to Nessism. I pulled it from one of his previous posts. I wanted it for my records

Then kudos to Nessism.  Credit where due.  Well done!

Good Ridin'
slmjim & Z1BEBE

My eBay NOS OEM regulator showed up today and all is well. It's putting out just under 15v at 4,000 rpm. I'll definitely pm you NESSIM, if this one craps out.