Make the rear wheel turn until you find the position where chain is tightest. Set the vehicle on the side stand. Push down the chain at the point of measurement and release. Measure the distance between the "aperture" upper profile and pin centre.
The read distance must be: 9 to 11 mm.

Important
If the drive chain is too tight or too slack, adjust it so that tension reading will fall within specified range.
To adjust the tension remove the rear splash guard (sect. 7 - 13, Removal of the swingarm).
Slacken off the two clamp screws (1) that secure the rear wheel hub to the swingarm.
Fit the hook spanner code 88713.1038 Inserting its tooth in the eccentric hub (2).
Rotate the eccentric hub (2) to obtain the correct chain tension.
Turn counter clockwise to tighten the chain; clockwise to loosen (from chain side).
Important
An incorrectly tensioned chain will lead to accelerated wear of the transmission components.
If the screws (1) are removed, lubricate with specified grease underhead and thread, then tighten the screws (1) to the torque of 35 nm +/- 5% (sect. 3 - 3, Frame torque settings) proceeding with sequence 1-2-1.

Warning
The correct tightening of the fixing screws of the eccentric hub is essential for the safety of the rider and the passenger (sect. 3 - 3, Frame torque settings).
Refit the rear splash guard (sect. 7 - 13, Refitting the swingarm).
Adjusting the steering head bearings
Checking brake pad wear and changing brake padsOverhauling the rear swingarm
Inside the swingarm (8), in correspondence with the pivot point on the frame,
there is a pair of ball bearings (10) and a
spacer (11) on the rh side, and a pair of roller bearings (6), with sealing
rings (5), on the lh side.
To change the bearings, proceed as follows.
Remove the shims ( ...
Gear change pedal
When released, the gear change pedal (1, fig. 96)
Automatically returns to rest position n in the centre. This is
indicated by the instrument panel light n (2, fig. 4) Coming on.
The pedal can be moved:
down = press down the pedal to engage the 1st gear and to
shift down. At this point the n ...
Horn not working
Fault codes
Dds: horn diagnosis -> short circuit to ground (s.C. Gnd).
Dashboard: the error "claxon" (horn) is shown on the service display. The eobd
warning light activates.
Wiring diagram
Db dashboard connection, s horn button. 5 Blue/white - b/w, 1 red/blue - r/b,
db 19 purple/bl ...