Nine times out of ten, it's the cable, even though it might look intact. Your local Select (PGO) dealer will be able to supply one for somewhere around $40 (give or take a bit). If it's not the cable, it could be the speedo drive that it mounted on the front wheel.
Put the scoot up on the main stand, remove the cable from the drive on the front wheel, and have a look in the cable hole on the drive unit as you spin the front wheel by hand. The little flat tab inside turns slower than the wheel, but if it is turning, then that one is eliminated. Re-attach the speedo cable.
Next, pull the dash apart so you can get your fingers on the knurled upper end nut of the cable, and undo it. You'll see a piece of inner cable sticking out. Again, spin the front wheel, and see if that piece of inner cable is turning. If not, then the cable has had the biscuit. If it is all turning properly, then it could be the dash, although that is less likely than the cable or drive unit...
Good luck with it.
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