On the back of the gauge is two little adjusters, they may be hidden behind cork plugs. Pull the gauge out and reconnect it. Empty the fuel tank. Switch on the ignition Watch where the gauge settles to. Adjust the adjuster with a small electrical screwdriver until it reads Zero Use something like a length of metal coat hangar wire suitably bent lift the float up fully. Adjust the other adjuster until the tank reads full. Check the empty posi