06 yamaha overcharging

[rick62]

I'm trying to figure out a 06 Yamaha voltage regulator problem. at a high rev the limiter puts out upwards of 16+ volts which cooked the old battery. I replaced the battery with a new one and put a used VR in and it's doing the same thing. The voltage seems to fluctuate with the throttle held steady. I checked another Yamaha that was the same year and it read a steady 15v . would a bad ground somewhere cause this fluctuation? I believe the used regulator is ok.