Use the micrometer to measure at several points around the ring.
Piston Ring Thickness Standard:
Top [A] 0.77 
0.79 mm (0.0303
0.0311 in.)
Second [B] 0.78 
0.79 mm
(0.0307 
0.0311 in.)
Service Limit:
Top 0.70 mm (0.0276 in.)
Second 0.71 mm (0.0280 in.)
If any of the measurements is less than the service limit on either of the rings, replace all the rings.
NOTE
When using new rings in a used piston, check for uneven groove wear. The rings should fit perfectly parallel to the groove sides. If not, replace the piston.
Piston Ring Groove Width Inspection
Piston Ring End Gap InspectionUpper Fairing Assembly Removal
Remove:
Lower Fairings (see Lower Fairing Removal)
Center Inner Fairing (see Center Inner Fairing Removal)
Upper Inner Fairings (see Upper Inner Fairing Removal)
Windshield (see Windshield Removal)
Disconnect the front turn signal light lead connector [A]
(both sides).
Remove the bo ...
Gear Position Switch Removal
Remove:
Oil Pump (see Oil pump Removal in the Engine Lubrication
System chapter)
Engine Sprocket (see Engine Sprocket Removal in the
Final Drive chapter)
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Disconnect the connector [A].
Remove:
Screws [A]
...
Swingarm Bearing Removal
Remove:
Swingarm (see Swingarm Removal)
Collar [A]
Oil Seals [B]
Sleeve [C]
Circlip [D] (Right Side)
Special Tool - Inside Circlip Pliers: 57001-143
Remove the ball bearing and needle bearings.
Special Tool - Oil Seal & Bearing Remover [A]: 57001-1058
...