My gas gauge reads very oddly. I put 6 gallons slowly into my standard new design tank behind the seats and eventually it reads almost full. I drive around 100-120 miles and the gauge goes down to a little under 1/2 tank, just as it should. Then, as I drive I watch the gauge go down to below empty with the empty warning light on over the next 10 miles or so. I put 6 more gallons in the tank. No more will go in. The gauge doesn’t show that any gas has been added for 20 miles or so.

I removed the seat and firewall and pulled the 2 rheostat/float mechanisms. Both worked perfectly up and down to the book resistance specs. I replaced the oval one and manipulated the float up and down through the other round opening. The float was free at all times and clear of the round opening float. I was thinking of using a boroscope to look down the gas fill pipe to see if the tank is really full. Other than that, I don’t have a clue of what to try next. Why does the gauge go from just under 1/2 to empty on 10 miles? Is it really empty? Am I filling the tank with 6 gallons and the gauge is showing the correct amount? Am I fooling my self about the floats not binding and working properly? Should I have stayed home instead of going to the counterinaugural ball when Nixon was elected?