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:
Tank filler plug
Note
To open or close the tank filler plug using the active
key, set the metal part in the middle position, as shown on
page 86.
Opening
Lift the cover (1, fig. 100) And insert the active or passive key
into the lock. Give the key a 1/4 turn clockwise to unlock.
Lift the plug (2, fig. 101) ...
Refitting the primary drive gears and checking backlash
Fully degrease the crankshaft splined end and the corresponding spline on the
primary drive gear.
Position the spacer (c) onto the crankshaft.
Fit the driving gear (b) onto the crankshaft with the oil pump drive sprocket
facing the crankcase.
Temporarily secure the gear with the was ...
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 ...