Small Engines (Lawn Mowers, etc.): Murray 13.5 hp 2003 model, drive train, safety switch

Question
My drive train belt broke, so I had it replaced.  I cut grass for about an hour after and had to go inside and when I shut off the mower it backfired.  When I tried to crank it again it backfires several more times.  I replaced the spark plug and looked at the coil.  I made sure that the coil was lined up with the magnets on the flywheel, but my mower will not crank, it just spins around and around without firing.  Any help would be greatly appreciated.

Answer
 Hello Philip:

 Set the Coil at .020in from the Flywheel. Is the Spark Plug Firing? If No, then Disconnect the Coil Shutoff Wire and Check for Fire. If Fire now, then a Safety Switch or Bad wire is Preventing the Coil from Firing. Send me the Model Numbers Off of the Mower and Off of the Engine, Please. With these Numbers I can View Breakdown of the Mower and the Engine and Better Assist you. Hope this Helps. Let me know what Happens, Please. I enjoy knowing the Outcome. Thanks.

 Good Luck

 Respectfully

 John