Replace the wheel rotation sensor if it is cracked, bent, or otherwise damaged.

Rear Wheel Rotation Sensor Installation
Wheel Rotation Sensor Air Gap InspectionDFI Servicing Precautions
There are a number of important precautions that should
be followed servicing the DFI system.
This DFI system is designed to be used with a 12 V sealed
battery as its power source. Do not use any other battery
except for a 12 V sealed battery as a power source.
Do not reverse the battery ...
ZX1000JB/KB Models
1. Run the fuse box 2 lead in front of the rib for the fuse box 2.
2. Seat Lock Cable
3. Hook the licence plate light lead and the left turn signal light lead on
the projection of the tool
kit case.
4. Rib for Fuse Box 2
5. Run the starter relay lead in back of the rib for the fuse box 2 ...
Engine Sprocket Installation
Replace the sprocket washer and axle cotter pin.
Install the engine sprocket onto the output shaft.
Apply molybdenum disulfide oil solution to the threads
and seating surface of the engine sprocket nut.
Tighten:
Torque - Engine Sprocket Nut: 145 N·m (14.8 kgf·m, 107
ft·lb)
NOTE
...