Small Engines (Lawn Mowers, etc.): rear tine tiller backfiring, rear tine tiller, briggs and stratton

Question
I have a 3 year old Craftsman Rear Tine Tiller with Dual rotating tines.  It has a 7.0 HP Briggs and Stratton engine.  I have maintained it according to the manual.  It seems to start and run fine.  The problem I have is when I shut it off.  It almost always backfires.  The carburator and air filter look clean and the spark plug is new.  The choke is completely off shortly after starting.  Any ideas why it would backfire like that?

thanks,

Lee

Answer
 Hello Lee:

 Are you allowing the Engine to Idle for 2 Minutes Before Shutting Off the Engine. The Carb Also may be Running a Little Rich which Causes UnBurnt Gas Vapors to build up in the Muffler.  Also the Muffler May not be Venting the Exhauxt Properly. Most Times its Not Allowing the Engine to Idle for 2 Min.  Then the Carb Adjustment. Then the Muffler Replacement.  Hope this Helps.

 Good Luck

 Respectfully

 John