RV Repair: Generator and fuel tank, gas gauge, loose fittings

Question
I have a 77 dodge robinhood rv with the 440 engine. My genset is an onan. When we put fuel in the fuel tank it starts overflowing under the rv at about 15 gallons. The gas gauge is accurate. I have looked everywhere for loose fittings, lines etc..question: could this be attributed to "some type" of overflow line going to genset,?? i was thinking maybe a line is clogged and it's sending it back to fuel tank?? (since rv's won't send fuel at 1/4 tank, we never have enough fuel to use the genset) Thanks in advance!

Answer
are you sure you dont have a hole in the tank?  Is it overflowing or spilling out?  Tanks usually draw from the top of the tank.  The draw tube for the generator is probably hovering in the tank, above the 1/4 mark.  If the tank has a hole, and you dont want to repair it.  You could try using a longer draw tube for the generator.  Try using a draw tube that goes to the bottom of the tank.  Just remember to watch your fuel guage, so you dont run out at the camp ground.