Wont start left out in the rain - ZX-6R Ninja kawasaki Motorcycles

Check the main fuse, it may have blown
Check that on/off switch hasn't shorted out, when you hit the start button you should be sending power to your solenoid which sends power to the starter motor.

If your stator/ rotor cover seal is bad, water may have got on the stator and corroded.
If it filled with water then its shorted out.
Start at the battery with a test light and work your way through your wires to see where you loose power.
For example: If you dont have spark, unplug your coil and see if you have power to the coil, if you do have power to the coil then the coil is bad.
If you dont have power to the coil, then the coil is probably good once you get power restored to it.
Trace the wire back to see where it looses power, it could be in the ignition switch.