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 dataSolenoid starter
Remove the protection cover (a).
Undo the screws (2), taking care to collect the spring washers (3).
Remove the starter motor-solenoid cable (4) and the solenoid-battery cable (5).
Remove the starter solenoid (1) sliding it upwards.
Checking operation of the starter solenoid
To ...
Removing the valves
Raise the rocker arm (3) and remove the opening shim (5) from the valves with
a pair of pliers.
Push down the closing rocker arms (16) and (4) and the closing shim (7).
Remove the half rings (6) from the valves with a magnetic screwdriver. Extract
the closing shims (7) from the valve ...
Refitting the rear sprocket
Check the cush drive bushes (6) condition and, if necessary, replace them by
removing them from the flange.
Refitting is the reverse of removal.
Apply recommended grease on the rear sprocket flange (5) external diameter.
Place the rear sprocket flange (5) on sprocket (17) by inserting it ...