When your vintage Kawasaki lights begin to dim, and the electric starter won’t kick over, the battery is the first place to check. If the battery is good though, and still won’t hold a charge, the fault is likely with the stator (generator) or the regulator/rectifier. At the first sign of battery drain, perform a voltage check on the stator (follow your repair manual guidelines).
If all is well, perform your manual’s suggested regulator/rectifier tests. Odds are, the problem is one, or both, of these components. Z1 stocks KZ1000 stators, CB750 stators, GL1000 stators and ZX1100 stators. We also carry new regulator/rectifiers for vintage Japanese motorcycles like the Z1, VMAX, GL1100, CB650, KZ750 and many more.