Signs to replace a regulator rectifier:
Bike died on me last week, and finally had time today to go out and look at her. Charged the battery to right above 12.3V (using a trickler) and cranked her up.
After letting her warm up a bit, I rev'd her up and around 3k rpm the rectifier had smoke coming out of it. The harness has a nice burn mark on it now, and I can see some melted plastic on the plug to the rectifier.