Honda FF 300 Owner's Manual page 32

Differential lock operation
For normal operation set the differential lock lever in the UNLOCK
position. This improves tiller's turning ability.
LOCK
UNLOCK
When the ground is soft and one wheel tends to slip or when only one
side is to be tilled, set the differential lock in the LOCK position. This
improves the tiller forward movement ability.
Move the differential lock lever after the main clutch has been
disengaged and the tiller has stopped.
When moving the tiller, set the differential lock lever in the UNLOCK
position.
If the differential lock lever is operated with the main clutch lever
squeezed, the differential lock mechanism may be damaged.
Operate the differential lock lever with the main clutch lever
disengaged.
When the tiller is running on a slope or uneven ground, set the
differential lock lever in the LOCK position.
Do not try to turn the tiller at high speed. The tiller turns quickly,
which leads to unstable driving of the tiller and possibly causes
injury to the operator and/or the bystanders.
Do not try to turn the tiller on a slope. The tiller turns quickly to an
unexpected direction, possibly causing personal injury and damage
to the tiller as well as to the property.
LOCK
DIFFERENTIAL LOCK LEVER
UNLOCK
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