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 dataStarter motor
Power:
0.7 Kw/12 v
Direction of rotation:
counter clockwise viewed from power take-off side.
The starter motor is highly compact and reliable and therefore rarely gives
any type of problem. In case of troubles,
ensure that the starter motor cable terminal is properly tightened under the n ...
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 ...
Reassembly of the connecting rods
Before starting, check that the crankshaft main bearing journals and big-end
journals are free of burrs or evident signs of
machining: if necessary, clean the surfaces with very fine emery cloth and oil.
Check that the grooves are in perfect condition with no signs of forcing.
Clean the cra ...