If the measurement is under service limit, replace the piston.

Piston Diameter
Standard: 75.959
75.974 mm
(2.9905
2.9911 in.)
Service Limit: 75.81 mm (2.985 in.)
Cylinder (Upper Crankcase) Wear Inspection
Piston Ring, Piston Ring Groove Wear InspectionSpark Plugs
The standard spark plug is shown in
the table. The spark plugs should be
replaced in accordance with the Periodic
Maintenance Chart.
Spark plug removal should be done
only by a competent mechanic following
the instructions in the Service Manual.
Spark Plug
A. Plug Gap ...
Inner Tube Inspection
Visually inspect the inner tube [A].
If there is any damage, replace the inner tube. Since
damage to the inner tube damages the oil seal, replace
the oil seal whenever the inner tube is replaced.
NOTICE
If the inner tube is badly bent or creased, replace
it. Excessive bending, followed by ...
Starter Clutch Removal
Remove:
Torque Limiter (see Torque Limiter Removal)
Transmission Assy (see Transmission Assy Removal)
Starter Clutch Shaft Holder Bolt [A]
Starter Clutch Shaft Bolt [B]
Starter Clutch Shaft Holder [C]
Remove the starter clutch shaft [A] using a suitable M8
bolt [B].
Take ...