Small Engines (Lawn Mowers, etc.): eagle 1 engine leaks fuel out the air filter, engine leaks, gas leaks

Question
Hi
I have a craftsman 6.75 hp lawnmower with an eagle1 engine.  Model number 917.377690.  After I use the lawnmower for 10-15 minutes and shut it off gas will slowly leak out the air filter for about 10 minutes.  So much gas leaks out that I need to put a rag under the filter.   The lawnmower will not start if I try to start it while the gas is leaking out.  I have to pull the sparkplug and clean it off and remove the air filter.  At this point it will start but smoke for a few minuts.  Any suggestions what I should do?
Thanks
Craig

Answer
Would have to be a faulty float needle and seat in the carburetor. When the level of fuel reaches a certain amount in the bowl the float moves up and presses the needle valve into the valve seat closing off any more gas from entering. (Same theory as your toilet tank float at your home). If it becomes worn, or dirt has lodged itself between them this occurs. You need to remove the carburetor, then the bowl on it and clean it out, then for the cost of the needle or needle and seat in some models, replace them for the coast of 3-4 dollars. .....Tom