If fuel level shown on the Q is low when the tank is full and vice versa, the fuel sensor type setting is wrong. See Settings – Boat – Fuel sensor. Normally the setting in Buster boats should be A type (US type sensor). The Phantom is an exception. If Yamaha Helm master is installed the fuel information is coming through NMEA2000 and the Qs should be configured to have 2 fuel sensors. One with NMEA2000 instance id 0 and one with id 1.