Small Engines (Lawn Mowers, etc.): Briggs and Stratton not starting, briggs and stratton, ohv motor

Question
I have a Craftsman riding mower. It is the I/C Platinum 15.5 HP OHV. Motor model # 28N707. Type 0173-01. Mower model # 917.258534. When attempting to crank the engine it will turn over but will not start. I changed the spark plug and it still will not turn over. It seems the carburator is pumping the fuel. Please let me know if you have any suggestions.

Answer
Does it turn over or not?  Turning over means it will spin.  Does it spin.  If yes does it have spark.  These are must questions.  Carbs don't pump fuel they atomize fuel in a controlled mist conducive to explosion under compression.  If fuel is "pumping" out you need to clean the carb.  Buy a carb kit and absolutely replace the needle and seat.