Originally Posted by Birken Vogt

As to the capacity, say your tank is 4 feet long and 2.5' in diameter. Find the area of the circle. Divide the 2.5' by two to get the radius of the tank (1.25'), now square the radius and you get 1.5625. Multiply that by pi (3.14) and you get the area of the tank end to be 4.9 square feet. Now multiply that by the tank length, I said 4 feet, and you get 19.6 cubic feet roughly. Now multiply that by 7.48 to get the gallons, 147 gallons in this case but you can only fill (IIRC) 80 or 90 percent of that. Does that make sense I hope? The formula I just described is (D/2)^2*pi*L where D=diameter and L=length of tank.

The other question sounds like the fuel tank sender is "plumb broke". Replace it.

Birken