I have an `07 Road King, and have an opportunity to buy a speedo/tach combo at about half what a new one costs. What I need to know is whether the odometer data is stored in the ECM, and if so will a new speedo show the mileage stored in the ECM or does the speedo store it too? And if that's the case, can a used speedo be initialized for the correct mileage for another bike? My bike only has 2500 or so miles on it so it's not like I want to "reduce" the miles showing. I just don't want problems later on if my speedo shows different mileage than the ECM...

 

Mileage is stored in the speedo, so your gonna show whatever the new one your buying has.

Legally all you have to do when selling is disclose that speedo was changed at xxxxxx miles on bike and xxxxxxx miles on speedo so that actual vehicle miles can be calculated.