Just Plain Bill
XS650 Addict
I wish I had an answer for you but I don't. Try a search for it otherwise start a new thread
If you have a variable speed/reversible drill, and a 50d (maybe 40d?) nail, you can hammer the nail end square (or grind it) to fit the speedometer/tach drive, cut the head off and use the nail in the drill to spin the instruments and test their functionality. Let the speedometer run long enough to turn the odometer over for a mile or so.