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 InspectionCylinder (Upper Crankcase) Wear Inspection
Split the crankcase (see Crankcase Splitting).
Remove the pistons (see Piston Removal).
Assemble the cylinder (upper crankcase) [A], the cylinder
head [B] and the cylinder head gasket [C].
Tighten the cylinder head bolts (see Cylinder Head Installation
in the Engine Top End chapter).
...
Rebound 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
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Front Wheel Rotation Sensor Signal (Service Code 27)
Front Wheel Rotation Sensor Signal Inspection
The front wheel rotation sensor sends the signal to the
ECU through the KIBS hydraulic unit (KIBS equipped
models). For other than KIBS equipped models, the
signal is sent directly to the ECU.
The ECU uses the wheel rotation sensor signal for KTRC
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