If the display function does not work, replace the meter unit.

Check 3-6: Neutral Indicator Light (LED) Inspection
Meter Unit Circuit (ZX1000J Model)Battery Removal
Turn off the ignition switch.
Remove the front seat (see Front Seat Removal in the
Frame chapter).
Slide the red cap [A].
Disconnect the negative (–) cable [B] and then positive
(+) cable [C].
NOTICE
Be sure to disconnect the negative (–) cable first.
Remove the band [D] ...
Idle Speed
The idle speed inspection should be
performed in accordance with the Periodic
Maintenance Chart.
This motorcycle is equipped with the
Idle Speed Control valve. If the idle
speed is disturbed, inspection of the
idle speed control should be done by
an authorized Kawasaki dealer.
NOTE
While ...
Throttle Body Assy Installation
Apply a thin coat of grease to the throttle cable lower ends.
Fit the accelerator cable end [A] and the decelerator cable
end [B] into the throttle pulley.
Install the clamp [C] securely.
Install the throttle body assy holder clamp bolt heads [A]
outside as shown in the figure.
...