Ducati Diavel Workshop Manual page 680

Cylinder head assemblies: timing system
Position the tool code 88765.1623 with legend "UP" and the arrow facing the cylinder head cover.
Place the pins of tool 88765.1623 in the exhaust side pulley seat (G) manually.
Manually tighten the knobs with tool code 88765.1623 until they stop.
With a torque screwdriver (H) tighten the knob nuts of the tool with part no. 88765.1623 to the torque of 2 Nm ± 10%.
Fit the horizontal cylinder timing belt around the camshaft pulleys and pass it behind the idler pulley.
Note
If the used belts are to be refitted, position them in their original direction of rotation and on their original cylinder.
Fit the tensioner pulley (9) and the washer (7) on the pin of the cylinder head.
Apply grease to the tensioner pulley pin threads and to the contact face of the nut (8).
Start the nut (8).
Check the timing belt tension and adjust if necessary as described in the paragraph Measuring the timing belt tension
values (Sect. 6 - 11) of the horizontal cylinder head belt.
Once the required tension has been reached make sure that the nut (8) retaining the tensioner (9) is tightened to a