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

Check 3-6: Neutral Indicator Light (LED) Inspection
Meter Unit Circuit (ZX1000J Model)Rebound Damping Force Adjustment
To adjust the rebound damping force, turn the rebound
damping adjuster [A] to the desired position.
The standard adjuster setting is the 1 3/4 turns out from
the fully clockwise position.
Rebound Damping Force Adjustment
...
Vehicle-down Sensor Installation
Be sure to install the rubber dampers [A] and collars [B]
on the bracket.
The UP mark [A] of the sensor should face upward.
WARNINGIncorrect installation of the vehicle-down
sensor
could cause sudden loss of engine power. The
rider could lose balance during certain ...
Cooling System Flushing
Over a period of time, the cooling system accumulates
rust, scale, and lime in the water jacket and radiator. When
this accumulation is suspected or observed, flush the cooling
system. If this accumulation is not removed, it will clog
up the water passage and considerable reduce the efficiency
...