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

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyExploded View
AL: Tighten the two clamp bolts alternately two times to ensure even
tightening torque.
HG: Apply high-temperature grease.
R: Replacement Parts
WL: Apply soap and water solution or rubber lubricant.
Specifications
WARNINGSome replacement tires may adversely
affect h ...
Handlebar Removal
Remove:
Steering Damper (see Steering Damper Removal)
Clutch Lever Clamp Bolts [A]
Clutch Lever Assembly [B]
Left Switch Housing [C]
Handlebar Weight [D]
Left Handlebar Grip [E]
Remove:
Front Master Cylinder [A] (see Front Master Cylinder Removal
in the Brakes chapter)
...
Mode-switching
Depress the S-KTRC button on the left handlebar switch
to change the mode. The mode can be changed only when
the throttle grip is closed completely.
The S-KTRC OFF can be selected only when the motorcycle
is at a stop. Changing to mode 1 from S-KTRC OFF
is possible while riding.
NOTE
...