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 InspectionGear Position Switch Installation
Securely place the springs [A] and pins [B] into the holes
[C] of the shift drum.
Apply grease to the new O-ring [D].
Install the gear position switch [E].
Apply a non-permanent locking agent to the threads of
the gear position switch screws [F].
Tighten:
Torque - Gear Position Swit ...
Wheel/Tire Damage Inspection
Remove any imbedded stones [A] or other foreign particles
[B] from tread.
Visually inspect the tire for cracks and cuts, and replace
the tire if necessary. Swelling or high spots indicate internal
damage, requiring tire replacement.
Visually inspect the wheel for cracks, cuts and dents ...
Air Intake Duct Assembly (US, CA and CAL Models)
Install the dampers [A] and seal [B] as shown in the figure.
Fit the holder [C] to the air intake ducts [D].
Projections [E] and Holes [F]
Grooves [G] and Ribs [H]
Tighten:
Torque - Air Intake Duct Assembly Screws [I]: 1.5 N·m (0.15
kgf·m, 13 in·lb)
Turn the plug [J] so that ...