today i was riding and my speedomoter decides to start acting a fool i know that the speeds it was showing where not correct and usually gains and lowers numbers just as fast as im getting into or out of. Does anyone have any idea what it could be? It is a 2006 CBR600RR.

 

What bike and year?

If its newer, its possible someone, or you by accident pressed the button on the gauge cluster and switched the miles per hour to kilometers per hour. See if it says KPH anywhere instead of MPH.