Hey, on some Honda's there are 2 different "tits" that the fuel line will fit on.

If you confuse them...one should be open.....or vacuum line (cant remember) you are putting gas in the "side" of carb, not down through the float needle. It will flow through, fill everything, and run out on ground till you shut er off!

Just look to see that you didn't put the fuel line on the wrong place. OR, if there is another "inlet"

What you are describing sounds familiar to me...don't ask why