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 padsChecking brake and clutch fluid level
The levels should not fall below the min marks on the
respective reservoirs.
If the level is too low, air can get into the circuit, thus
impairing the efficiency of the system.
Brake and clutch fluid must be topped up and changed at the
intervals specified in the scheduled maintenance table ...
Reassembly of rear shock absorber - rocker arm - linkage assembly
Once the needle roller bearings (9) have been removed from the rocker arm
(18), upon reassembly fit a new needle roller
bearing (9) on drift part no. 88713.1071 And lubricate with recommended grease.
Support the rocker arm and drive the needle roller bearings into the rocker arm
bore until t ...
Adjusting the steering head bearings
Note
To adjust the steering bearing clearance, follow what is described in
sect. 4 - 3, Adjusting the steering head bearings.
If the problems found are not solved, check the wear of steering bearings (6)
and replace them, if necessary, as described
in paragraph "removal of the steering head c ...