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

Check 3-6: Neutral Indicator Light (LED) Inspection
Meter Unit Circuit (ZX1000J Model)Fuel Injector Output Voltage Inspection
NOTE
Be sure the battery is fully charged.
Turn the ignition switch to OFF.
Remove the ECU (see ECU Removal).
Do not disconnect the ECU connector
Connect a digital meter [A] to the connector (gray) [B] with
the needle adapter set.
Special Tool - Needle Adapter Set: 57001-1457
...
Economical Riding Indicator
When the operator is driving the motorcycle
for optimum fuel-efficiency, the
economical riding indicator appears on
the multifunction meter to indicate favorable
fuel consumption. Monitoring
the economical riding indicator can
help the rider maximize fuel efficiency.
A. Economical Riding ...
Rear Master Cylinder Installation
Replace the washers that are on each side of hose fitting
with new ones.
Install the brake hose [A].
Touch the brake hose to the stopper [B] of the rear master
cylinder.
Tighten:
Torque - Brake Hose Banjo Bolt: 25 N·m (2.5 kgf·m, 18 ft·lb)
Install the master cylinder, the brack ...