'74 TX650a voltage at battery intermittantly drops

[gruvola]

My restored '74 started bucking about 10 miles into a ride. I had to rev it fairly high to get off the line at stop lights (no power and then all of a sudden hold on!), but made it home. It idles great. But checking the voltage at the battery, it's 12.5 when not running, about 13.8 running then intermittantly drops to single digits and bounces back to 13.8.

So far I've tried
- rotor and brushes: I misread resistance on my rotor (duh!) and bought a new one with brushes. It acted the same.
- reg/rec: I replaced the reg/rec with a model correct solid state one
- Changed the entire wiring harness:  I suspected bad grounding and I had reused the old one at resto 3 years ago. I checked grounds as I rewired, filing off powder coat on frame where applicable.

It runs exactly the same. Which means I have a few good used spare parts.

The stator resistance across all wire combinations seems good but I suspect an intermittant short. Should I pull the trigger on that too?

Thoughts anyone?

[jetmechmarty]

Fixed?