1) Press and hold down the MODE and CLOCK buttons.
2) Turn on the ignition. The display will remain blank.
3)Wait until the display shows the letters "MPH". Then you can release the buttons.
4) Wait for the instruments to go through the normal start up and you will notice that it now displays MPH.
On the very early models the change could only be made within the first 6km
hope this helps. [you might need to use a screwdriver or other object to push the buttons as they are normally stiff]
GILERA [now piaggio etc] DEALER 1967 - 2008
gilera mech
May 2008