@jtown, I have to admit being a little bit overwhelmed with this pages of measuring.
Usually in a shop I would start to search in a case like yours, with this.
- full battery test, in your case ok
-all fuses out and new ones in (decorrode prongs)
- disconnect the plug between stator and regulator/ rectifier
pls see link
- measure with multimeter on AC each of this three YELLOW cables from stator during motor running, should be 50-70 volts AC at
cable 1-2, 2-3, 3-1 same voltage on each
-if this shows this amount, your stator is fine
NEXT
-connect this plug from stator to regulator again
-start motor
-let it idle, should be 12.9-13.6 volts DC on your battery
-gas up to 3-4000 rpm, should be around 14.8V
If not, several measures, your regulator is faulty.
Maybe att link helps.
Another culprit might be the minus cable which leads from your battery to your starter motor, there I had a rotten endpiece once on a LIKE 200i.
Maybe check this link beneath too.
https://www.kymcoforum.com/index.php?topic=31637.0If this all comes out positively we have to see into your starter relais.
The one with a red and black plastic cap on it.
If you put jump start cables on your starter directely, what happens?
If it starts happily is either your starter relais faulty or mentioned minus cable rotten, or both.
https://www.kymcoforum.com/index.php?topic=31878.0