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 canisterRemoval of the tool tray
To remove the tool tray unit from the lateral footrests, loosen the screws
(40) and remove the splashguard (20).
Undo the screws (15) and remove the cover (16).
Move the wiring branch from the seat (s) on the tool tray.
Loosen the screws (24) to remove the tool tray unit (23) from ...
General 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 ...
Refitting the water pump
Clean the seat on the cover, any parts you intend to reuse, and the impeller
shaft. Then refit as follows.
Fit on the impeller (10) shaft the mechanical seal (9) as indicated in the
figure.
Apply specified lubricant to facilitate the insertion.
Bring the mechanical seal fully home on th ...