Mine seems to work just fine, Usually when the light comes on I have about a gallon left. By their nature MC fuel tanks are hard to measure very accurately due to their somewhat convoluted shape. The first inch down may be a gallon while the next inch down may be 3/4 gallon. Very non linear. I'd have it checked though since mine does seem to be accurate at least when the light comes on, Still I zero the odometer at every fill-up