Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionPiston Ring Groove Width Inspection
Measure the piston ring groove width.
Use a vernier caliper at several points around the piston.
Piston Ring Groove Width
Standard:
Top [A] 0.82 0.84 mm (0.0323
0.0331 in.)
Second [B] 0.82 0.84 mm
(0.0323 0.0331 in.)
Service Limit:
0.92 mm (0.036 in.)
Second 0.92 mm (0.036 in.)
...
Valve Guide Installation
Apply engine oil to the valve guide outer surface before
installation.
Heat the area around the valve guide hole to about 120
150°C (248 302°F).
NOTICE
Do not heat the cylinder head with a torch. This will
warp the cylinder head. Soak the cylinder head and
heat the oil.
Usin ...
Camshaft Runout Inspection
Remove the camshafts (see Camshaft Removal).
Set the camshaft in a camshaft alignment jig or on V
blocks.
Measure the runout with a dial gauge at the specified
place as shown in the figure.
If the runout exceeds the service limit, replace the
camshaft.
Camshaft Runout
Standard: TIR ...