I have 1982 and that and number of others have only that as maximum speed reading. The result is that many early -80 US model bikes have a broken speedometer needle, as the bike reaches that speed well below top rpm. It was government idea at the time that requiring manufacturers provide bikes with those speedometers, people wouldn´t be driving any faster, as the general speed limit due oil crises was 55miles per hour. Models sold elsewhere had higher reading over 200km/hr. (123mph). Like all the other countries. That was changed later on the decade.