If any one of the parts is damaged, replace the mechanical seal as a unit.
Rubber Seal [A] Mechanical Seal [B]

Water Pump Housing Assembly
RadiatorFront Forks/Rear Shock Absorber Operation Inspection
Pump the forks down and up [A] 4 or 5 times, and inspect
the smooth stroke.
If the forks do not smoothly or noise is found, inspect the
fork oil level or fork clamps (see Front Fork Oil Change in
the Suspension chapter).
Pump the rear seat down and up [A] 4 or 5 times, and
inspec ...
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 ...
Air Suction Valve Inspection
Remove the air suction valve (see Air Suction Valve Removal).
Visually inspect the reeds [A] for cracks, folds, warps,
heat damage or other damage.
If there is any doubt as to the condition of the reeds, replace
the air suction valve as an assembly.
Check the reed contact areas [B] of ...