Rob Lentini and I have been having a discussion on the "adjustability" of K bike speedo's with Rob not being able to find the adjustment potentiometer. I found it and this describes it.
The adjustment pot is on the side away from the stepper coil. It is towards the lights and unless you have separated the speedo from the rest, you will not see it. It is behind the gears that drive the odo, and on the little board that you can see in the unassembled view. This is the board that the 3 pin connector plugs into. This is a high (12V) signal. I think some of it is robbed to drive the electronics for the frequency sensitive circuit that drives the meter that functions as a speedo indicator. Even then it is well buried with the adjustment almost exactly in line with the plastic sheet. This is just like the tach where they obviously don't want you to get your fingers in there.
Now, how to drive it and adjust it. That is for a later time.
But for those who are adventuresome and have time on your hands, you too can adjust your odo.
Brian Curry, Chester Springs, PA, USA