Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionEngine 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
...
Wiring Diagram (US, CA and CAL without KIBS Models)
ZX1000JC
ZX1000JD
...
City Light (LED) Removal/Installation
Remove:
Upper Fairing Assembly (see Upper Faring Assembly
Removal in the Frame chapter)
Headlight (see Headlight Removal)
Remove the screws [A], and take the city light [B] off the
upper fairing assembly.
Installation is the reverse of removal. Note the following.
When inst ...