If the cams are worn down past the service limit, replace the camshaft.
Cam Height Standard:
Exhaust 35.043 
35.157 mm
(1.3796 
1.3841 in.)
Intake 38.243 
38.357 mm
(1.5056 
1.5101 in.)
Service Limit:
Exhaust 34.94 mm (1.376 in.)
Intake 38.14 mm (1.502 in.)
Camshaft Runout Inspection
Camshaft Chain RemovalOil Level Inspection
Check that the engine oil level is between the upper [A]
and lower [B] levels in the gauge.
NOTE
Situate the motorcycle so that it is perpendicular to the
ground.
If the motorcycle has just been used, wait several minutes
for all the oil to drain down.
If the oil has just been changed, ...
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
...
ECU Removal
NOTICE
Never drop the ECU especially on a hard surface.
Such a shock to the ECU can damage it.
Remove the upper air cleaner housing (see Air Cleaner
Element Replacement in the Periodic Maintenance chapter).
Lift up the ECU [A] with rubber protector [B] to disconnect
the connectors [C]. ...