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 InspectionIdle Speed Inspection
Start the engine and warm it up thoroughly.
With the engine idling, turn the handlebar to both sides
[A].
If handlebar movement changes the idle speed, the
throttle cables may be improperly adjusted or incorrectly
routed, or damaged. Be sure to correct any of these
conditions before rid ...
Stem, Stem Bearing Removal
Remove:
Upper Fairing Assembly (see Upper Fairing Assembly
Removal in the Frame chapter)
Front Fender (see Front Fender Removal in the Frame
chapter)
Front Wheel (see Front Wheel Removal in the
Wheels/Tires chapter)
Steering Stem Head with Handlebars (see Handlebar
Removal)
Fron ...
Idle Speed
The idle speed inspection should be
performed in accordance with the Periodic
Maintenance Chart.
This motorcycle is equipped with the
Idle Speed Control valve. If the idle
speed is disturbed, inspection of the
idle speed control should be done by
an authorized Kawasaki dealer.
NOTE
While ...