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 InspectionChain Slack Adjustment
Remove the cotter pin, and loosen
the axle nut.
Loosen the left and right chain adjuster
locknuts.
A. Axle Nut
B. Cotter Pin
C. Adjuster
D. Locknut
If the chain is too loose, turn out the
left and right chain adjusters evenly.
If the chain is too tight, turn in the left
...
Charging Condition Inspection
Battery charging condition can be checked by measuring
battery terminal voltage with a digital voltmeter [A].
Remove the seat (see Seat Removal in the Frame chapter).
Disconnect the battery terminals.
NOTICE
Be sure to disconnect the negative (–) cable first.
Measure the battery ...
Crankcase Assembly
NOTICE
The upper and lower crankcase halves are machined
at the factory in the assembled state, so the
crankcase halves must be replaced as a set.
With a high flash-point solvent, clean off the mating surfaces
of the crankcase halves and wipe dry
WARNINGGasoline and low flash-poin ...