Small Engines (Lawn Mowers, etc.): Fuel issue, briggs stratton engine, white lawn tractor

Question
I currently own a white lawn tractor with a 12 hp briggs & stratton engine.  I just recently got it out for this years season.  It will start, however, it dies after about 1 minute of run time.  I noticed that at that time gas is pumping from the breather hose back into the carb and the breather,flooding the engine.  What would cause this?

Thanks,
Chris Johnson

Answer
There is either a problem with the inlet needle and seat or the float.  Either way, fuel level in the carb is not being properly regulated.  You will to thoroughly clean the carb and inspect the needle and seat for debris or wear.  You also need to make sure the float isn't full of fuel and has sunk (you should hear fuel in it if you shake it near your ear).  Hope this helps.