One fuel line is rhe fuel input, which connects to the weighted pickup filter inside the tank. Did you fish the pickup filter out of the tank and attach to your new line? Also did you leave line long enough to allow the pickup to move to the bottom of the tank?

The other line is the return from the carburetor purge. It send excess fuel back to the tank. Some manufacturers used to let the purge gas just dump on the ground.

If you re-did the circuit correctly, next step is to then disassemble carb and clean out passages. Carb is probably gummed up from old gas.