Probably a broken speedo needle, Its an easy fix most of the time, just remove the 3 bolts down at the axle on the clutch side, you will see the cable running down to it, remove it and there should be a square needle that goes into a hole in the axle, that is most likely broken, hopefully its not stuck in the axle, that can be fun to get out, but if it is still retriveable it should pull out, get a new needle and pop it back in to the housing, sometimes they can be rusted in the housing and might take some work to get out.
hopefully that isn't confusing.
EDIT: it should pop out of the housing, it just gets pushed in, When i saystuck in the axle, sometimes the needle can break off flush with the axle shaft, making it impossible to retrieve. most of the time it just corrorodes right at the point where it gets installed in the housing....
hope that helps ya out