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 InspectionRebound Damping Force Adjustment
To adjust the rebound damping force, turn the rebound
damping adjuster [A] to the desired position.
The standard adjuster setting is the 1 3/4 turns out from
the fully clockwise position.
Rebound Damping Force Adjustment
...
Stem, Stem Bearing Removal
Remove:
Upper Fairing Assembly (see Upper Fairing Assembly
Removal in the Frame chapter)
Front Fender (see Front Fender Removal in the Frame
chapter)
Front Wheel (see Front Wheel Removal in the
Wheels/Tires chapter)
Steering Stem Head with Handlebars (see Handlebar
Removal)
Fron ...
Swingarm Installation
Visually inspect the chain guide [A].
Replace the chain guide if it shows any signs of abnormal
wear or damage.
Apply a non-permanent locking agent to the threads of
the chain guide bolt [B].
Apply plenty of grease to the lip of the oil seals [A].
Be sure to install the oil seals ...