Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionFuel Tank and Cap Inspection
Visually inspect the gasket [A] on the tank cap for any
damage.
Replace the gasket if it is damaged.
Check to see if the water drain pipe [B] and fuel breather
pipe [C] in the tank are not clogged. Check the tank cap
breather also.
If they are clogged, remove the tank and drain it ...
Water Pump Housing Assembly
NOTICE
Do not reuse the mechanical seal and oil seal.
Apply high-temperature grease to the new oil seal lips [A].
Press the new oil seal into the housing with a bearing
driver [B] until it stops at the bottom surface [C] of the
housing.
Special Tool - Bearing Driver Set: 57001-1129
...
Cam Wear Inspection
Remove the camshafts (see Camshaft Removal).
Measure the height [A] of each cam with a micrometer.
If the cams are worn down past the service limit, replace
the camshaft.
Cam Height
Standard:
Exhaust 35.043 35.157 mm
(1.3796 1.3841 in.)
Intake 38.243 38.357 mm
(1.5056 1.5101 in. ...