Motor Motor Crank-case I Crank-case I Drive shaft Drive shaft Cylinder - Piston Cylinder - Piston Valves cover Valves cover Cylinder head - valves Cylinder head - valves Valves pads Valves pads Front cylinder timing system Front cylinder timing system Rear cylinder timing system Rear cylinder timing system Gear box Gear box Clutch I Clutch I Clutch II Clutch II Clutch cover Clutch cover Ignition unit Ignition unit Cover Cover Lubrication Lubrication Secondary air Secondary air Water pump Water pump