I have no clue on the calibration as I think mine was within 2-4 miles of being accurate. Many times, I used the RPM mode and just adjusted the +/- toggle using hand signals from the rider. Sorry I could not help but once you find the answer, make sure you post it in the forum for others to see.
I just bought a 2007 X2 a few months ago and I found that the MC Cruise (MPH setting) isn't calibrated. Just wondering if I can grab some advice from you. After some testing with my buddies 2005 X10 and an iphone MPH app I found that the MC Cruise says I'm doing ~29 when in reality I'm actually going ~21. Is there a way to re-calibrate the MC Cruise to show the correct MPH on the gauge?