Have you tried a calibration re-set ?
1. Empty the tank and fill it with 1 gallon (or your desired quantity you want the reserve light to come on at).
2. Make sure you have access to the diagnostic port of the Motorcycle and identify pin 3 and pin 4.
3. Turn the ignition on.
4. On the diagnostic port, short pin 3 (brown/black) and pin 4 (brown) for two seconds. (Make sure you have the CORRECT pins - you don't want to short Battery voltage to GROUND by mistake).
5. The tank reserve light should flash quickly. When the flashing ends, the calibration is complete.
