You can check the resistance at the float after disconnecting thew wire, should be about 65 ohms, when fully empty if you know how much fuel you have in the tank and you are getting around the 65 ohms mark then the float maybe full of fuel. You can also check to see if you have fuel in the tank, by removing the rubber hose and shining a light in the tank opening and use a wooden rod or other devise to see what the level is in the tank.