Usa models are equipped with an additional system with an evaporative emissions canister that prevents fuel fumes from being discharged into the atmosphere.
The breather hose (4) is connected to the canister filter (1); when the fuel has been filtered, it is returned through the hose (2) to the horizontal (a) and vertical (b) intake manifolds via the hoses (2a) and (2b). Drainage pipe (c) and the hose (5) vent to the ground.
For correct positioning of the connection hoses consult the indications given below.

Evaporative emissions canister
Removal of the evaporative emissions canisterRefitting the cylinder head assemblies
Warning
To prevent oil leaks past the contact area between cylinders and
crankcase, each time the head is removed, cylinder and
piston must be removed as well to clean the mating faces of crankcase and
cylinder and restore the spoiled gaskets and
o-rings and apply again liquid sealant (sect. ...
Adjusting throttle control free play
The throttle twistgrip must have free play of 1.5×2.0 Mm in
all steering positions, measured on the outer edge of the
twistgrip. If necessary, adjust it using the adjusters (1 and 2,
fig. 135) Located on the headstock on the right-hand side of
the vehicle.
Adjuster (1) is for throttle o ...
Reassembling the electrical components support
Check the presence of clips (1), (9) and (24) on the support (5).
Check the presence of rubber pads (6) and (8) and of cable grommet (7).
Check that the voltage regulator (3) and the solenoid starter (18) are in
place on the support (5) with their wiring as
shown.
The horn (22) mus ...