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 InspectionECU Communication Error (Service Code 39)
ECU Communication Line Inspection
When the data is not sent from the ECU to the meter unit
for more than about 10 seconds, the service code 39 is
displayed.
The data is sent through the CAN communication line.
The service code 39 is detected with the meter unit.
When the user mode, this commun ...
Spring Preload Adjustment
Remove the rear shock absorber from the frame (see
Rear Shock Absorber Removal).
Loosen the locknut and turn out the adjusting nut to free
the spring.
Special Tools - Hook Wrench T=3.2 R37: 57001-1539
Hook Wrench R=35: 57001-1580
To adjust the spring preload, turn in the adjusting n ...
Sprocket Wear Inspection
Visually inspect the engine and rear sprocket teeth for
wear and damage.
If the teeth are worn as illustrated, replace the sprocket,
and inspect the drive chain wear (see Drive Chain Wear
Inspection in the Periodic Maintenance chapter).
Worn Tooth (Engine Sprocket) [A]
Worn Tooth (Rear ...