Speedometer repair

Now that I've confirmed that my speedo in my midget is quite off ( Pretty
close up to about 40 MPH then has a hard time getting higher after that and It
is actually getting stuck at about 55 MPH occasionally) does anyone know how
to go about fixing and recalibrating a Speedometer in a 1977 midget?  (By the
way Ron, thanks for the link to Yahoo for the speed calculator.)
Dick
77 Midget - "Maggie"


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