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

Rear Wheel Rotation Sensor Installation
Wheel Rotation Sensor Air Gap InspectionSteering Damper Oil Leak Inspection
Visually inspect the steering damper [A] for oil leakage.
If the oil leakage is found on it, replace the steering
damper with a new one (see Steering Damper Removal/
Installation in the Steering chapter).
ZX1000JD/KD [B]
...
Cylinder (Upper Crankcase) Wear Inspection
Split the crankcase (see Crankcase Splitting).
Remove the pistons (see Piston Removal).
Assemble the cylinder (upper crankcase) [A], the cylinder
head [B] and the cylinder head gasket [C].
Tighten the cylinder head bolts (see Cylinder Head Installation
in the Engine Top End chapter).
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Rocker Arm/Tie-Rod Bearing, Sleeve Inspection
NOTICE
Do not remove the bearings for inspection. Removal
may damage them.
Visually inspect the rocker arm, or tie-rod sleeves [A] and
needle bearings [B].
The rollers in a needle bearing normally wear very little,
and wear is difficult to measure. Instead of measuring,
inspect the ...