Small Engines (Lawn Mowers, etc.): Briggs and Stratton P317770348e1

Question
I have pretty much rebuilt my lawn tractor engine, a brigg and Stratton p31777.  I have replaced the fuel pump,fuel filter, ignition magneto, air filter, fuel needle valve, gaskets, head assembly (due to a bent pushrod and hole through the head, made sure the cam and shaft were line up with the dots, new spark plug and valve clearance set correctly, I believe, and unfortunately the engine still will not start.
It wants to, but fires like once or twice and then just cranks.  Lots of fuel smell, and fuel coming out of the exhaust.  
Is it possible the needle valve is stuck, or the valves are not adjusted correctly?

Answer
It could be the valves, the inlet needle or even the flywheel key could be sheared.

Did you follow the procedures detailed on the Briggs website?

http://www.briggsandstratton.com/eu/en/support/faqs/servicing-the-valves

You Tube video:

http://www.youtube.com/watch?v=DuZfUldb6Yg
FYI, I use a drinking or WD-40 straw to feel the piston comes up to top-dead-center on the COMPRESSION stroke.

Did you check the flywheel key?
Eric