Small Engines (Lawn Mowers, etc.): Carb. Air tube, vent tube, air vent

Question
I'm repairing a craftsman 4.5 hp push mower, fuel is leaking from the air vent tube, where exactly does that tube go, and what might be causing this problem, thanks

Answer
Most likely it the the atmospheric vent from the carb.  This just allows air to enter the carb bowl.

Your problem is most likely caused by a leaky inlet needle and seat.  I would also check the float.

Google "Tecumseh carburetor rebuilding" for detailed directions on how to fix the carb.
Let me know if this helps.
Eric