Small Engines (Lawn Mowers, etc.): Riding Lawn Mower

Question
I have a 12.5 Hp Yard Machine With a Walbro Carberator on it which just happened to start spraying gas out from the tail pipe. Pulled it off had someone clean it up and put it back on and the same thing happened, and Im and the end of my whits.Have you any thoughts on the subject.

Answer
I am assuming you have a Briggs and Stratton engine.

The most likely cause of you problem:

1) Leaking inlet needle or bad seat.  Does you needle have a rubber tip on it?
2) Bad float. Do you have a brass or plastic float?

Did you drain and re-fill the engine oil to remove any gas that may have entered the engine oil?

What is the engine model, type and code number?

Eric