Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionExhaust Butterfly Valve Actuator Removal
NOTICE
Never drop the exhaust butterfly valve actuator especially
on a hard surface. Such a shock to the actuator
can damage it.
Remove:
Front Seat (see Front Seat Removal in the Frame chapter)
Clamp [A]
Screws [B] and Washers
Slide the covers [A] and loosen the lock nuts [B] ...
Wiring Diagram (US, CA and CAL without KIBS Models)
ZX1000JC
ZX1000JD
...
ECU Identification
Most countries have their own regulations, so each ECU
has different characteristic. So, do not confuse ECU with
each other and use only the ECU for your model. Otherwise,
the motorcycle can not clear the regulation.
ECU Identification
ZX1000JB/KB
ZX1000JC /KC
...