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

Water Pump Impeller Disassembly/Assembly
Water Pump Housing DisassemblyCheck 2-3: Intake Air Temperature Inspection
Disconnect the intake air temperature sensor connector
[A] (see Intake Air Temperature Sensor Removal in the
Self-Diagnosis System chapter).
Connect the variable rheostat [B] to the R/BK lead [C] and
BR/BK lead [D] terminals.
Turn the ignition switch to ON.
Read the temperatur ...
Tachometer
The tachometer shows the engine
speed in revolutions per minute (r/min,
rpm).
On the right side of the tachometer
face is a portion called the “red zone”.
Engine r/min (rpm) in the red zone is
above maximum recommended engine
speed and is also above the range for
good performance.
...
Rebound Damping Force Adjustment
The rebound damping force adjuster
is located at the upper end of the rear
shock absorber.
A. Rebound Damping Force Adjuster
B. To increase damping force
C. To decrease damping force
Using a screwdriver turn the rebound
damping force adjuster clockwise
to increase rebound damping or ...