Thanks for all the assistance. I finally got around to figuring this out and wanted to share the solution that worked best for me.
On-Bike Stator Check
How to test a motorcycle stator
https://www.youtube.com/watch?v=5v2LtHlvcqI
To check the stator while on the bike:
- Locate the regulator/rectifier
- There are three yellow cables to link the regulator to the stator
(I tested mine after swapping in a new regulator)
On the open side of the regulator/stator connector using the three ports:
- Set your multimeter set to OHMS
- Test the three stator wires by alternating the positive/negative leads across the three ports:
A > B
B > C
C > A
(see 1:42 on the video above, btw - sequence is not overly important just alternate)
- Verify that nothing goes to ground from these wires by touching to the battery
(see 2:06 on the video above)
Next test the stator while the bike is running
- Plug in the stator connector attached to the regulator/rectifier
- Start the bike
- Set the multimeter to VAC
On the back side of the stator connector test the ports
(Similar to OHMS test this VAC tests is against the three ports)
Phase 1 to 2
Phase 2 to 3
Phase 3 to 1
(see 2:17 of video link provided)
When motor is cranked the voltage on the stator cables should increase exponentially as the RPM increases.
(see 2:51 of video)
On-Bike Rectifier/Regulator Check
See this video (https://www.youtube.com/watch?v=kDx3zgOLShY)
To perform regulator diode check on bike:
- Set multimeter to diode function
- Find the regulator/rectifier on the bike
- Either unplug (or expose the back side of) the stator and diode connector(s)
(can be one or two connectors, the stator connectors will normally be yellow wires)
- Separately test the forward/reverse bias of the positive and negative diode between the three stator leads. (see 2:08 of the video for how to do this)
The regulator/rectifier can apparently have other issues that can cause problems but this test is all that can be done on the bike.
On-Bike Battery Check
- Locate the battery positive (+/red cable normally) and negative (-/black cable normally) terminal; check the plastic on the battery near the terminal to be sure of terminal charge.
- Set multimeter to VDC
- Test battery at rest (no engine on, touch multimeter positive/negative cables to respective battery terminals); it should be between 12.5 and 12.8 (mine was 12.66)
- Test battery with engine on and note the rise in VDC when engine is revving.
BTW - Replacing the regulator required 6 screws and little to no elbow grease. Next up I need to consider replacing the stator.