After some help, I have Honda Fireblade CBR 900RRV on a 1997 plate. Have an a fault on the speedo I have change the drive on the front sprocket and the fault is still there. It looks like the little black box that the sprocket drive plugs into. I am having trouble finding a replacement part. I have taken the black box out and plugged the speedo sensor from the front sprocket directly into the loom. when riding the bike at about 30mph the speedo shows 80mph. so I need this black box what ever it is