Small Engines (Lawn Mowers, etc.): 6.5 HP* Briggs & Stratton engine sounds like it is misfiring, exhaust valve seat, briggs stratton engine

Question
I have a 6.5 HP B&S Troy Built lawnmower it is only two-years old, it sounds like it is misfiring and is having trouble starting.  Before it ran out of gas the last time it started running properly then after I filled the tank again it is sounding like it is misfiring again, almost to the point of stalling out.  What suggestions can you give me to fix this problem?

Answer
 Hello Tiffany:

 1- This sounds like a Burnt Valve. Grind and Relap the Valves should cure this problem. 2- There could be Carbon Built up around the Exhaust Valve Seat. Clean Valve Port. Grind and Reseat the Valve. If you are Going to Grind and Reseat One Valve; Do Both. Hope this Helps.

 Good Luck

 Respectfully

 John