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 camshafts
Unscrew and remove the screws (7) and the o-rings (8) from the cylinder head
covers.
Remove the cylinder head cover (6).
Remove the gaskets (4) and (9).
Repeat the same procedure for the other cylinder head cover. Unscrew the
screws (3) securing the camshaft supports.
Withdra ...
Final drive
Circlip
Nut
Washer
Nut
Rear sprocket flange
Cush drive bush
Inner ring
Chain
Spacer
Chain cover
Screw
Nut
Lock washer
Front sprocket
Spacer
O-ring
Rear sprocket
Spare parts catalogue
Diavel abs gearbox
Diavel abs rear wheel axle
Diavel carbon
abs
gearbo ...
Reassembly of the control unit
Insert the control unit (4) into the protecting sheath (5) and position it on
the airbox.
Position the relay supporting bracket (2) by starting and tightening the
screws (1) to a torque of 6 nm +/- 10% (sect. 3 -
3, Frame torque settings), and connect the control unit connectors (3).
...