At least on mine, the indicator decal on the inside started to turn white and then back to black, then white, then black.....may be temperature related but recently has just gone white and stayed there. New fuel indicator units are on the order of $43 and just to see the fuel quantity wasn't worth it. Pulled the unit out and using a drill chuck (hand use only, don't want to drill thru the cap) and small drill, moved the pointer to the empty, quarter, half, three quarter and full positions and made a small concave divot at the end of the pointer at each location with the drill. Then used a black permanent marker to color the divot so it's easily seen. Bingo. $43 saved. To reinstall the trick is to slide the rubber gasket off the head and reinsert into the tank opening and then insert the gauge unit, slightly lubricated, into the rubber gasket and just push until it seats. You can't just install it with the gasket on the unit.