what is the correct battery for my kawasaki zx 10 b1 model 1989 ?

The stock battery is Yuasa brand, YB14L-A2. Be sure to keep the water level in the battery above the top of the plates in each cell. Also, check the voltage across the battery terminals while the bike engine is running around 2500rpm. The voltmeter should read around 14.5 volts. If it reads 15 or higher the voltage regulator is probably bad.