
A verrrrrry long time, like on the order of days.  I had the pleasure of
doing that once (playing with the speedo cable) and with my B&D heavy duty at
full speed (600 rpm) all the speedo ever got up to was 30 MPH.  Now if you go
a high speed drill and ran it at say 4000 rpm, you could get 200 MPH out of
it.  (If you speedo doesn't burn out.)  Anyways, to roll a 100000 Mile
odometer would take 22 days or so.  Much easier just to take the speedo
apart.

Thought I'd share.  BTW, all this info was obtained legally  :-)

