Follow the suggestions given so far and you'll find the problem. Given my past dismal experience with Tillotsons, however, I suspect the soft pot metal inlet threads have been damaged by an over-zealous tightening they received in the past. But all is not lost if those threads are bad! The carburetor can be saved.
One way to fix this condition is to use a gas-resistant epoxy to bed a new brass male-tipped inlet adaptor fitting in the carburetor. Choose an adaptor that not only fits in the carb's inlet hole, but will also accept the fuel line fitting. Vendors may sell such a fitting, such as for a Model "B" carb. Possibly your local hardware store can help. Take your carburetor half and old fuel line with you and test fit the new adaptor. Allow the epoxy to cure before installing the fuel line.
As recommended by "CT Jack", replace that coiled fuel line with the proper straight one. The Model A uses a gravity feed fuel delivery system and anything that interrupts the free flow of fuel will adversely affect performance. Passing through those coils on a horizontal plane (at the lowest point) will definitely mess up fuel flow, especially when climbing steep hills. The carb will suffer from fuel starvation. You will be able to use the correct original fuel line if you install the adaptor I recommend.
Marshall