Small Engines (Lawn Mowers, etc.): Lawnmower Engine is Flooding, excessive blowby, briggs stratton engine

Question
Hi Marc,

 I have a 2yr old TroyBilt Lawn tractor LTX-1842 with Briggs&Stratton engine Model # 31D777 . When the engine is run in fast idle the engine is being flooded by fuel or oil.There is breather tube located before the throttle plate. Fuel or oil is coming out of the tube and is being sucked into the carb.This is causing the spark plug to foul and engine to smoke.The engine runs in slow idle.Where is the excess fuel or oil coming from?  

Answer
The only thing coming out of the breather tube would be oil.  Check to make sure the oil level isn't excessively high.  The only reason other than a high oil level (but not likely for a 2 year old machine) is excessive blowby caused by the engine being worn out and compression leaking to the crankcase.  Hope this helps.