Small Engines (Lawn Mowers, etc.): brigg engine no start, fly wheel, keyway

Question
i have a troy bilt 20 hp rider it has new plugs new fuel filter new air cleaner and pre filter it has spark and the fuel pump is good and i can hear the solinoid engaging motor cranks but does not start could it be the keyway  on fly wheel or what???

Answer
Take a compression reading, You have ignition (spark) and you tell me the fuel pump is good, so i assume you have fuel,  but do you have fuel entering the carb?  Spray some carb cleaner into the carb then crank the engine over.  Does it run for a few seconds and quit? if so you have some carb issues, perhaps your main nozzle is plugged.

If you have a compression tester, get a reading first.  You should have at least 40psi of compression.