Got a Fault with my 06 rsv factory speedo. it clocks up mile ok & revcounter works fine but the speed reading is very erratic goes from zero to full speed and any speed inbetween at all road speeds even at idle just reving the engine without moving/some timew it will also flick betweem mph & kmh. fault just started during a dry journey ( bit of a thrash) stayed with me eversince.only done 3200 miles in total/ any body got any clues?: