whenever I go over ride over 60-70mph my speedo reads the wrong milage ie I know the distance is say 15 miles my speedo reads 25-30 miles. does anyone know why this might cause this?

 

kawi speedos usually read 10% high, and as such the odometer should tick 10% faster as well, but thats a little excessive, you may have a problem with your odometer. Are you running stock sprockets? (only matters if your getting speed from the trasmission instead of the front wheel, dunno what your riding...)