Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionExploded View
11. ZX1000JD/KD
AD: Apply adhesive.
AL: Tighten the two clamp bolts alternately two times to ensure even tightening
torque.
G: Apply grease.
L: Apply a non-permanent locking agent.
Specifications
...
Shifting Gears
Close the throttle while pulling in the
clutch lever.
Shift into the next higher or lower
gear.
Open the throttle part way, while releasing
the clutch lever.
For smooth riding, each gear position
should cover the proper rate of speed
shown in the table.
WARNINGDownshifti ...
Front Wheel Rotation Sensor Removal
NOTICE
The wheel rotation sensor should be handled carefully,
never struck sharply, as with a hammer, or allowed
to fall on a hard surface since the wheel rotation
sensor is precision made. Be careful not to get
water or mud on the wheel rotation sensor.
Do not try to disassemble or repair t ...