Small Engines (Lawn Mowers, etc.): hard start 18 hp briggs, hp briggs, lawn chief

Question
Hi Eric,
 I have a Lawn Chief 18 hp industrial b&s motor some times it will turn over fine and start,go to start it a gain and it will kick back and most of the time it will need to be boosted on off the charger on boost. I took the plugs out there no restriction spins like crazy plugs back in, it like wants to kick back a few times and start and start it also pulls the life right out of the battery trying to start it. Belts are off it still does the same thing. Could it be timing, I have know idea how or where to begin to set the timing.

Answer
Igntion timing is maintained by the flywheel key.  Flywheel keys rarely shear or fail in the larger engines.  Mechanical timing is controlled by the cam, timing gear and valves.   

Have you ever checked or adjusted the valves?

Before tearing into the engine, make sure the battery has been charged and load tested.  Most autoparts stores will test the battery for free.

Before reconnecting the battery, clean the battery posts and cable ends with a wirebrush.  I have fixed a lot of hard starting problems just by cleaning the battery connections.

Let me know what you find.
Eric