The speed is restricted by means of a reed switch which is mounted in the rear of the speedo. It tells the CDI when the bike reaches 60mph and stops the revs from increasing. To remove the speedo restriction take off the headlamp cowl and pull out the spring clips holding the speedo in. Then unscrew the speedo cable and lift up the clock. You will see two things in the bottom of the clock casing. One is round and is the light bulb for the clock, the other is white and oblong. This is the reed switch and you carefully prise it out and tuck it to one side out of the clock. I suggest you put it in a bag and tuck it as far away as possible. Do not cut or disconnect it. will this make any change on its own (not got a dep yet) and can it be left in the back of the housing but removed from the clock
IF YOU FOLLOW THE LESD FURTHER DOWN JUST UNPLUG THE CONNECTER BLOCK,MY 2002 DTR DID 58 MPH THE DAY I GOT IT,WITH THE RESTRICTER UNPLUGGED IT DID 70 MPH..