Mercury 9.9 EH Manual page 76

To adjust the load of the remote control lever, turn the throttle
friction adjustment screw on the front of the remote control box.
Turn clockwise to increase the friction and counterclockwise to
decrease it.
a - Turn counterclockwise to decrease the friction
b - Turn clockwise to increase the friction
c - Throttle friction adjustment screw
FEATURES & CONTROLS
a
b
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c
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