Yamaha YXR660FAS Owner's Manual page 33

NOTE:
_
G When the switch is set to "LOCK", the dif-
ferential gear lock indicator light will flash
until the differential gear is locked.
When the indicator light is flashing, turn-
G
ing the steering wheel back and forth will
help the differential gear lock to engage.
Riding before the differential gear lock is
G
properly engaged (e.g., when the indica-
tor light is flashing) will cause the engine
speed to be limited until engagement is
complete.
_
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