Ducati MONSTER S4Rs Manuel D'utilisation Et Entretien page 113

The system disengages the starter motor as soon as the
engine starts.
If the engine fails to start, wait at least 2 seconds before
pressing the start button (2) again.
Allow the engine to start without turning the throttle
twistgrip.
E
Important
If the battery is flat, the system automatically
disables operation of the starter motor.
1
2
fig. 32
38