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 padsRemoval of the starter motor idler gear
Slide the gear pin (21) complete with the gear (19) and washer (20).
Warning
Pay attention to the washer (20) since it may fall inside the
crankcase half.
At this point, it is possible to remove the starter motor as described in
sect. 6 - 3, Starter motor. ...
Front brake lever
Pull the lever (1, fig. 94) Towards the twistgrip to operate the
front brake. The system is hydraulically assisted and you only
need to pull the lever gently.
The control lever (1, fig. 94) Features a dial adjuster (2, fig. 94)
For lever distance from the twistgrip on handlebar
adjustment.
...
The battery charging circuit and power distribution
On the diavel, the +15v (key on power) voltage does not come from a
conventional ignition key, but from pin 30 of the
hands free relay. This relay is switched to closed state by the hands free unit
when the latter enables power on for the
ignition and engine. The hands free relay receives +30v ...