Shimano BeastMaster 9000 Instruction Manual page 48

What is Rakuraku Mode?
Rakuraku Mode maintains line tension at the level you set.
In other words, the reel senses the tension (load) on the line
and automatically adjusts motor rotation speed to maintain a
constant tension.
48
It also has the following advantages...
• Rigs with only a light load can be recovered at maximum
speed without having to worry about adjusting motor speed,
which makes life easy and means that you can concentrate
on fishing.
• Adjust tension can quickly and easily using the Technical
Lever.
• Maximize rig strength by eliminating the tug of war that
occurs between the motor and the fish.
Setting Rakuraku Mode
• Settings are adjusted using the Technical Lever (see the
previous page for details).
1~4
• Settings are for dead slow.
At some tension setting the weight of the sinker can stop the
rig from being wound in. In such cases increase the tension.