Ducati Diavel Service Manual: Checking valve clearances
To check the valves clearance, it is necessary to have access to the cylinder head covers and then remove the components listed below.
Unscrew the two fixing screws (1) of the cover (2) according to the crankshaft.
Fit the tool handgrip 88713.0123 In the holes of the generator cover to be able to turn the crankshaft so that the valve on which the control is carried out is in rest position.
With the valve in the rest position, slide a feeler gauge between rocker arm (a) and the lowest side of the cam (b) to measure the clearance.
The clearances must be within the specified limits:
With the valve in the rest position, slide a feeler gauge between closing
rocker arm (c) and the highest side of the cam
(d) to measure the clearance. 
If detected values exceed the specified limits, replace opening and/or closing shims, as described in paragraph "removing the valves" (sect. 9 - 4.5), With an adequate height to obtain the specified clearance.
Note
Opening rocker arm shims measuring from 1.8 To 3.45 Mm and closing rocker arm shims measuring from 2.2 To 4.5 Are available as spare parts. The size is punched on the shim.
Remove the handgrip tool 88713.0123 From the hole of the generator cover.
Make sure that the o-ring (3) is fitted on the cover (2).
Refit the external cap (2) by tightening the two retaining screws (1) to a torque of 10 nm (min. 9 Nm - max. 11 Nm) (sect. 3 - 3, Engine torque settings).
Change timing belts
To replace the timing system belts follow the procedures described in paragraph "removal of the movable tensioner/timing belt" and "refitting the timing belts" (sect. 9 - 4.2).
Changing the engine oil and filter cartridge
Note
This operation has to be carried out with hot engine (but turned off)
because the oil in these conditions is more fluid and
its evacuation is faster and complete.
Remove the drain plug (3) w ...
Spark plugs replacement
Check the colour of the ceramic insulation around the central electrode:
an even, light brown colour indicates the engine is in good condition and
running at the right temperature.
Inspect the c ...
Other materials:
Timing system
Desmodromic (type) with four valves per cylinder,
operated by eight rocker arms (4 opening rockers and 4
closing rockers) and two overhead camshafts. It is operated
by the crankshaft through spur gears, belt rollers and toothed
belts.
Desmodromic timing system (fig. 159)
Opening (or upp ...
Tft - parameter setting/display
Warning
Any adjustments to the dashboard must only be carried out when the
motorcycle is stationary. Never operate the
dashboard controls while riding the motorcycle.
At the end of the check, the dashboard always displays as the "main"
indication the odometer (tot) on the left and the
averag ...
Removal of the control unit
Loosen the screws (1) and remove the relay supporting bracket (2), disconnect
the connectors (3) and remove the control
unit (4) from the vehicle.
...