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)

Engine
Performance dataGeneral maintenance indications
Useful tips
Ducati recommends that you follow the instructions below in order to prevent
problems and obtain the best end result:
When diagnosing faults, primary consideration should always be given to
what the customer reports about motorcycle
operation since this information can highli ...
Ignition coils
Introduction
The engine control system of the diavel includes two ignition coils: one for
the horizontal cylinder and one for the vertical
cylinder. These coils are installed directly in the spark plug wells. A diode is
installed on the secondary winding inside the
coil, which prevents the un ...
Removal of the exhaust system
Remove the silencer, as described in the paragraph "removing the silencer" of
this section.
Loosen the screws (28) and remove the exhaust by-pass valve cover (27).
Turn the exhaust valve pulley (a) to facilitate the throttle cable (25)
output.
Release the end fitting (b) of the cable ...