Yamaha BIG BEAR 400 Owner's Manual page 96

If you begin rolling backwards:
Keep weight uphill.
2WD: Never apply the rear brake
while rolling backwards. Apply the
front brake. When fully stopped, ap-
ply the rear brake as well, and then
lock the parking brake.
4WD: Apply both front and rear
brakes gradually. When fully stopped,
lock the parking brake.
Dismount on uphill side or to a side if
pointed straight uphill. Turn the ATV
around and remount, following the pro-
cedure described in the Owner's Manu-
al.
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