I have a 2016 Sduro with a Yamaha motor set up. The speedometer has been gradually not working to the point where the display only shows 0 mph not matter how fast i'm going. After which the motor stops working. The spoke magnet is centered. I've looked under the motor and the wire and connections seem to be in good shape. Any suggestions? I'm thinking i might need to get a new speed sensor but am not sure where to purchase in the US.