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

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyPrecautions
There are a number of important precautions that are
musts when servicing electrical systems. Learn and observe
all the rules below.
Do not reverse the battery cable connections. This will
burn out the diodes on the electrical parts.
Always check battery condition before condemning other
...
Gear Position Switch Installation
Securely place the springs [A] and pins [B] into the holes
[C] of the shift drum.
Apply grease to the new O-ring [D].
Install the gear position switch [E].
Apply a non-permanent locking agent to the threads of
the gear position switch screws [F].
Tighten:
Torque - Gear Position Swit ...
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 ...