Excessive handlebar play or the forks shaking in the steering head indicate that the play in the steering head bearings requires adjustment. Proceed as follows.
Unscrew the four screws (1), remove the two clamps (2) and remove the handlebar (3) from the steering head, positioning it out of the way so it does not hinder subsequent operations.
Slacken the clamp screws (4) securing the top yoke to both fork legs.
Loosen the clamp screw (5) that holds the steering tube to the top yoke.
Using service tool no. 88713.1058, turn the nut (6) to the specified torque (Frame torque settings).
Tighten all previously loosened screws to the specified torque (Frame torque settings).
Reposition the handlebar (3), fit the clamp (2) and tighten the four clamp screws (1) to the specified torque (Frame torque settings).