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

Check 3-6: Neutral Indicator Light (LED) Inspection
Meter Unit Circuit (ZX1000J Model)Clutch Cover Assembly
Replace the needle bearings and oil seal with new ones.
NOTE
Install the needle bearings so that the manufacture’s
mark face out.
Install the needle bearings [A] and oil seal [B] position as
shown in the figure.
Press the upper and lower bearings so that the bearing
surface [ ...
Coolant Level Inspection
NOTE
Check the level when the engine is cold (room or ambient
temperature).
Check the coolant level in the reserve tank [A] with the
motorcycle held perpendicular (Do not use the sidestand).
If the coolant level is lower than the “L� level line [B], remove
the upper fairing assembly (s ...
Liquid Gasket, Non-permanent Locking Agent
For applications that require Liquid Gasket or a
Non-permanent Locking Agent, clean the surfaces so
that no oil residue remains before applying liquid gasket or
non-permanent locking agent. Do not apply them excessively.
Excessive application can clog oil passages and
cause serious damage.
...