Fuel should not come out from the carburetor's breather port. It sounds like there is a problem - possibly the carburetor is flooding. When you have fully assembled the engine, with fuel in the tank and the fuel tap in the on position, disconnect the breather hose at the carburetor end. If fuel runs or drips steadily from any part of the carburetor, it sounds as if there is flooding, which is probably due to a needle-and-seat problem. Incidentally the breather hose probably fell off because of the fuel getting inside the hose, which makes it very slippery.
