Ok there is one thing that has occurs once and a while. The fuel gauge could have been cross wired. Take a Phillips screw driver and remove the 2 screws holding the instrument cluster to the handlebar. Remove the speedometer cable nut with a needle nose pliers carful not to let the nut slide down the cable. Now turn the cluster over and take out the two screw out of the back of the fuel gauge and pull the gauge out of the sleeve. You will see either 3 or 4 wires on the back of the fuel gauge. One wire can go to a light and does not have a screw attaching it to the fuel gauge there may be some glue around the wire. One wire is black do not move this wire. That will leave 2 more wires. Unscrew these 2 remaining wires and switch their positions and screw them back in. Before you attach everything back together turn on the key and see if the needle moves now? If this has solved the problem screw everything back in the reverse way they came out.
