Small Engines (Lawn Mowers, etc.): B&S 6.5hp lawnmower wont start, briggs stratton, tree root

Question
Hi
I have a Craftsman 6.5hp Briggs & Stratton lawn mower.  About 1 month ago, I hit a tree root.  The motor shut off and the blade bended.  The mower did start back up and as expected the grass was cut uneven.  

Today, I replaced the blade and tried to restart it.  But the mower won't restart.  The pulley sometimes pulls back forcefully.  I tried loosening the blade slightly but no luck.  Any suggestions, would be highly appreciated.

Thanks in advance,
 Jorge

Answer
 Hello Jorge:

 Replace the Flywheel Key. When the Mower Struck the Root it Damaged the Flywheel Key. Now the Flywheel is So Far Out of Time the Spark Plug is Firing at the Wrong Time with the Location of the Piston. Hope this Helps. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John