Z1OwnersClub GB

I have a charging voltage of 15.4 V at 5000 revs...is this OK?
Seems a volt to high to me..or acceptable?
Thanks

Too high.
Should be around 13.8v.

Regulator?

Weren't the early regs adjustable? Vaguely recall they were if you have an early birdcage type.

My original regulator

Maybe it was the rectifier then, it was a long time ago!

A rectifier is a semi conductor, it works one way but not the other, not adjustable either

I don't think I imagined it. What happens if you remove the three cross heads? Does it give you access to the circuit?
I vaguely recall it was just a matter of changing the tension of two contacts inside it?
If yours is toast anyway might be worth a look inside.

Hi.
Had same problems, not on a Z1 but on another vintage Kawasaki I have. I've had high voltage on 2 original rectifier / regulators. Common to see acid burns due to over charging battery boiling on the exhausts/frames on bikes back in the day including my recently acquired B2.
Alan

Mine also still has the original, voltage regulator and rectifier although arguably not in as good condition as your photos show, have tested it all on the bench using multimeter, however until its installed in the bike and got engine running its impossible to say how the components will perform. I'm all for originality where possible but where reliability is compromised i will replace with a combi unit. To keep it looking correct i will utilise the existing connector and mounting place. I know from previous posts the rectifier and voltage regulator were problematic, unusual for japanese made components as their usually ultra reliable, obv not in this case.

Hi Adrian,

I wonder if this might be the same problem I had with my Z550. I had a charging voltage of about 14.8V that was even higher when the lights were switched on. I assumed it was the regulator so fitted a new unit only to find the charging voltage remained exactly the same.
I then investigated online to see if I could find any more information. I found that the regulator takes a reference voltage from the ignition switch and used this to regulate output depending on load. However, with time the loom degrades particularly around the headstock where it is stressed regularly. Individual copper strands break (hidden by the insulation) which increases the resistance of the wire. Furthermore, any corrosion or contamination on the connectors can make matters worse. The low reference voltage causes the regulator to increase output I would start by checking the voltage or resistance drop on this wire.. If this is the culprit then it may be easier to run a new wire.

There is a chap in the US that makes regulator kits that do away with the need for this reference voltage wire.

Roadster Cycles
Jack Fleming
4603 west 163rd. street
Lawndale, California. 90260
310.766.5222

https://www.roadstercycle.com/

I hope the above is helpful.....

This short YouTube video explains it more clearly I think

https://youtu.be/sOvBV1z7cZ0

That site has some good info on it, the only thing im not sure of according to the wiring schematic the voltage reg senses the voltage and turns the field coils on and off to the Alternator thereby turning them on and off rapidly to maintain the desired voltage. Not sure if the Kawasaki alternator field coils are voltage excited or self excited if the latter then that arangement wouldnt work, you would need a diff method to interrupt the self excitation to turn coils on amd off to create regulator.
That rectifier does 50A way more then the original, although it wouldnt look anything like it so purists may not be impressed.