The bike started and ran on battery, so it's not wiring.
The stator output with the bike running 5k RPM is 0. ....Problem.
The oil that came out prior to pulling the cover was the ugliest oil I've ever seen.
The rotor has some mysterious crud in it that turned out to be soft and gummy.
The stator is clearly burned. I assume the burnt insulation is the crud in the stator.
Close up of stator badness:
There are several bolts to keep track off: some longer, some shorter, some washered. The dowel pins to align the case are the same diameter, but different length than the dowel pins which align the speed sensor. They can get mixed up (and did).
When re-assembling, the dowel pins and clutch push rod have to align, as well as a large dowel pin which sits in a boss inside the cover (this pin is the axle for what I assume was the starter gear). Doing that is tricky because the rotor magnets want to pull the stator/cover out of your hands for the last 1". You also have to keep a gasket in place while doing that. Not difficult, just fiddly and tedious.
The new stator output (3 yellow wires) against each other was right at 65V AC, where it should be. After re-plugging the harness, the battery sees 13-14.5V, again, good - the charging system is working,. I'll cross my fingers about the regulator/ rectifier and the battery longevity.
Several long rides have produced a slight smell of 'burning'. I'll have to check wire routing, and hope that it's just spilled oil cooking off.
An OEM stator was about $325, another $10 for a gasket. Two weeks without a bike starting on Labor Day = sucko. Getting around without my primary transportation = PITA. Wrenching on bike in poorly-lit garage until 1am = airbags.