If the surface is corroded or if the blades are damaged, replace the impeller

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyExploded View
10. US, CA, CAL and AU Models
11. ZX1000JD/KD
G: Apply grease.
L: Apply a non-permanent locking agent.
R: Replacement Parts
S: Follow the specified tightening sequence.
1. US, CA and CAL Models
2. ZX1000J Model
3. ZX1000K Model
4. AU Model
5. Face the large diameter side re ...
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
...
Exhaust Butterfly Valve Actuator Resistance Inspection
Turn the ignition switch to OFF.
Disconnect the exhaust butterfly valve actuator lead connector
(2 pins connector) [A].
Set the hand tester to the × 1 Ω range and connect it to
the exhaust butterfly valve actuator connector.
Special Tool - Hand Tester: 57001-1394
Measure ...