I tend to have the same thoughts as Ross....overtightening is a sure bet for a leak. Are the bolt holes blind, or do they go into the tank? Sealant on the bolts?
What a great deal for the new owner to be....bummer you have to let such an incredible machine go. Good luck with the sale. If I didn't already have a 2014, I would seriously consider this, that would be a great ride back to Komifornia!
Wish you were closer, I would gladly help out. Try unplugging most everything on the harness after the main harness and see if it still blows it. I would guess it's something in the ignition/ coil/starting or Charging side. Possibly the rectifier.