Portable fuel gauge for fuel tank

A fuel gauge adapted to extend into a fuel tank to reach and sense a level of liquid fuel extant in the fuel tank, the fuel gauge comprising

• a fuel cap including a housing adapted to mate with a fuel-tank filler neck included in the fuel tank, a seal plate having an inner surface arranged to face toward the fuel tank and an opposite outer surface arranged to face away from the fuel tank, the seal plate being coupled to the housing to move therewith, and a seal arranged to lie between the seal plate and the fuel-tank filler neck to establish a sealed union therebetween,
• a fuel-level indicator including a fuel-level display coupled to an outer surface of the seal plate, a needle coupled to the fuel-level display and arranged to move about a pivot axis aligned with the fuel-tank filler neck relative to the fuel-level display between an empty-tank position and a full-tank position, and a display lens coupled to the fuel-level display to define a sealed display space therebetween, and
• an indicator positioner including a buoyant float arranged to lie within the fuel tank and configured to float on a surface of the liquid fuel in the fuel tank to sense a level of liquid fuel extant in the fuel tank and a needle mover coupled to the buoyant float to covert up-and-down movement of the buoyant float into movement of the needle about the pivot axis, wherein the needle mover includes a magnetic arm coupled to the seal plate to rotate about an axis of rotation relative to the seal plate and a twistable-guide rod coupled to the magnetic arm to move therewith, the magnetic arm is arranged to lie in spaced-apart relation to the needle to locate the seal plate therebetween and is configured to provide a magnetic field to couple the needle to the magnetic arm through the seal plate to move the needle about the pivot axis.