How familiar are you with the Piaggio MP3 ?
For the electric starter to operate, not only does the ignition key have to be turned to the on position AND the ENGINE STOP SWITCH
be in the RUN position .....
BUT you must also APPLY REASONABLE PRESSURE to either of the BRAKE LEVERS.
On another note, the MP3 has an IMMOBILISER
There is a TRANSPONDER CHIP in the IGNITION KEY that is detected by the bike's "security system" and the CODE in it is read and compared to the one stored on-board.
I've never tried to start a MP3 with a key that has the wrong code or the transponder chip missing, BUT, if it is the same as my car (Ford Mondeo) the STARTER MOTOR DOES NOT TURN - NOT EVEN A CLICK