78 KZ 650 charging issue.

One of my 1977 KZ650s has Dyna-S igjition and the 1978 charging system on it and it only charges at about 12.5v. No good, but I rode it this way for 45,000 miles and it worked good enough to function and ride. I'm sure the Dyna -S is the problem. Another 1977 KZ650 using all the 1977 charging system and a Dyna-S charges fine, and another 1978 KZ650 with a Dyna-3 ignition charges fine as well.

loudhvx this is correct. I have measured this on both. My stock stator made 70V at 4000 rpm on my DC voltmeter. My aftermarket three phase makes about 56V evenly across all three contacts at 4000 rpm.

I have put all my wiring back in place now, made new pads for the gauges when I had it apart. Removed that old connector from the gauge lights to the harness. Rewired key switch back in. I have tested the bike running with everything except the headlight and I am at about 13.3-13.6 at idle. 14.5 above 3000 rpm. I am going to install the LED headlight and see now that goes. I ordered a voltmeter to run on the bars. I have been nervous to do more than about 10 miles because of the poor charging, With a meter and the new lights I will stretch that out if it holds voltage well enough.

The weather is getting warm and I want to ride this thing. Have only got the sportster out once this year because I keep wrenching on the KZ. Im ready to ride it.

UPDATE (Solved)

Got my LED dashlights and headlight in the mail. Once I got those installed, I wrapped the harness back up and fired it up. Running 13V at idle and almost 14V at 2000 rpm. I did get a small voltmeter to run while ridding. More or less 14.3V the entire ride unless I am stopped, then it stays around 13V unless I have the break pulled and signals on then it fluctuates a spec lower. I would image that if I did my running and signal lights all LED as well that it would be even better, but as it stands, I am just glad to be ridding. If you have to hide from the virus, you may as well hide on 2 wheels.

Now back to better problems to solve, like paint.

Thanks for all the advice all.