Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionOil Seal, Grease Seal
Do not remove pressed oil or grease seals unless removal
is necessary. Replace with new ones whenever removed.
Press new oil seals with manufacture and size marks facing
out. Make sure the seal is aligned properly when installing.
Apply specified grease to the lip of seal before installing ...
Connecting Rod Big End
Bearing Insert/Crankpin Wear Inspection
Remove the connecting rod big end (see Connecting Rod
Removal).
Cut strips of plastigage to crankpin width. Place a strip
on the crankpin parallel to the crankshaft installed in the
correct position.
Tighten the connecting rod big end nuts to the specified
torque (see Connecting Rod I ...
Valve-to-Guide Clearance Measurement (Wobble Method)
If a small bore gauge is not available, inspect the valve
guide wear by measuring the valve to valve guide clearance
with the wobble method as indicated below.
Insert a new valve [A] into the guide [B] and set a dial
gauge against the stem perpendicular to it as close as
possible to the cy ...