Motorcycle Questions? Ask a Mechanic.
When replacing a speedometer it is necessary to first copy the odometer information. This is a fraud prevention feature on HD speedometers. This is step done in different ways. The speedometer will display "No cal" and will not function until this step is completed.
If the speedometer is an HD accessory speedometer then there is a harness included in the installation kit with instructions on how to complete the odometer copy. Basically you use an included harness to plug the new speedometer into the data link connection and it will copy the mileage over.
If the replacement speedometer is a standard factory replacement then the mileage information will need to be entered using a digital technician at an HD dealer or another computer system, such as the Techno Research system, that some independent shops have. If this isn't done the same "No cal" will display and the gauge will not work.
If a used speedometer is installed it will display the same thing and I don't think there is a way to reset it for use on another bike.
I hope this helps. Thanks, P.J.