If they show any damage, replace it.

Caliper Fluid Seal Damage
Caliper Piston and Cylinder DamageStarter Motor Assembly
Install the positive brush assy [A] and the starter motor
terminal [B] as shown in the figure.
Replace the O-ring [C] with a new one, and install it.
Install:
Brush Springs [A]
Negative Brush Assy [B]
Turn the stopper side [C] to inside.
Tighten:
Torque - Brush Holder S ...
Replacement Parts
Replacement parts must be KAWASAKI genuine or
recommended by KAWASAKI. Gaskets, O-rings, oil seals,
grease seals, circlips, cotter pins or self-locking nuts must
be replaced with new ones whenever disassembled.
Assembly Order
In most cases assembly order is the reverse of disassembly,
howe ...
Technical Information - Electronic Steering Damper (ESD/ZX1000JD/KD models)
1) Overview
This model has an Electronic Steering Damper (ESD)
[A]. Unlike conventional manual adjustment method of
Kawasaki, damping characteristics are adjusted by the
electronic control unit.
2) Purpose
Designed to offer increased stability at high speed without interfering with
light ...