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

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyUpper Fairing Assembly Disassembly
Remove:
Upper Fairing Assembly (see Upper Fairing Assembly
Removal)
Headlight (see Headlight Removal/Installation in the
Electrical System chapter)
City Light (LED) (see City Light (LED) Removal/Installation
in the Electrical System chapter)
Remove the screws [A], and separate each ...
Before Servicing
Before starting to perform an inspection service or carry out a disassembly
and reassembly operation
on a motorcycle, read the precautions given below. To facilitate actual
operations, notes, illustrations,
photographs, cautions, and detailed descriptions have been included in each
chapter w ...
ECU Power Supply Inspection
Remove the upper air cleaner housing (see Air Cleaner
Element Replacement in the Periodic Maintenance chapter).
Visually inspect the ECU connectors.
If the connector is clogged with mud or dust, blow it off
with compressed air.
Remove the ECU (see ECU Removal).
Visually inspect the ...