Sure sounds like it's over charging. Do those bikes have a regulator as well as the rectifier? Or a capacitor that soaks up the excess charge?
Nice job on the vid.
2007 Suzuki DR650SE-2000 Buell M2 Cyclone-Plated 1995 XR600R-1989 Kawasaki KDX200-1984 Honda XL600R/XR650L Hybrid-1984 Honda CR500R-1984 Yamaha TT600L-1981 Honda XR500R-1980 Honda CB750F