As the tire tread wears down, the tire becomes more susceptible to puncture and failure. An accepted estimate is that 90% of all tire failures occur during the last 10% of tread life (90% worn). So it is false economy and unsafe to use the tires until they are bald.
If any measurement is less than the service limit, replace the tire (see Tire Removal/Installation in the Wheels/Tires chapter).

Tread Depth Standard:
Front 3.6 mm (0.14 in.)
Rear 5.3 mm (0.21 in.)
Service Limit:
Front 1 mm (0.04 in.) (AT, CH, DE) 1.6 mm (0.06 in.)
Rear 2 mm (0.08 in.) (Up to 130 km/h (80 mph)) 3 mm (0.12 in.) (Over 130 km/h (80 mph))
| WARNING Some replacement tires may adversely affect handling and cause an accident resulting in serious injury or death. To ensure proper handling and stability, use only the recommended standard tires for replacement, inflated to the standard pressure. |
NOTE
Wheel/Tire Damage Inspection
Wheel Bearing Damage InspectionOxygen Sensor Installation (Equipped Models)
NOTICE
Never drop the oxygen sensor [A] especially on a
hard surface. Such a shock to the unit can damage
it. Do not touch the sensing part [B] to prevent oil
contact. Oil contamination from hands can reduce
sensor performance.
Tighten:
Torque - Oxygen Sensor: 25 N·m (2.5 kgf·m, 18 ...
Engine Vacuum Synchronization Inspection
NOTE
These procedures are explained on the assumption that
the intake and exhaust systems of the engine are in
good condition.
Situate the motorcycle so that it is vertical.
Remove:
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Air Cleaner Housing (see Air Cleaner ...
Throttle Body Assy Holder Installation
Be sure to install the new O-rings [A].
Using a high flash-point solvent, clean off any oil or dirt
that may be on the silicone sealant coating area. Dry
them with a clean cloth.
Apply silicone sealant to any two positions of the new O
-ring.
Sealant - Liquid Gasket, TB1211F: 92104-0 ...