I wonder if the two yellow AC leads from the stator are sending current to anything? The AC rectifier for headlight is wired up, but as you pointed out I obviously have a DC headlight circuit. I'd like to parralel the two yellows into the battery charging system since my headlight is drawing off the battery, so it likely needs the boost. I don't want to smoke the rectifier/regulator in the process though.
I've got the meter out and put to use. What is known is the two purples from the stator put out good AC voltage disconnected and metered. They are the only AC feeding the rectifier, which passes the diode test. There is good AC coming from the yellow and orange leads on the stator, disconnected, and seen again at the wires to the little black plastic headlight regulator. All makes sense EXCEPT: headlight on when engine not running. Also, when running the RPMs have no affect on the brightness of the headlight. As much as I don't want to open the nacelle, might be the only way to sort this out.