Small Engines (Lawn Mowers, etc.): Misfiring Cub Cadet Model 2166, cub cadet, spark plug

Question
Tractor lost power and engine died.  Tried to restart.  It cranked for about a minute, then backfired out the exhaust. I replaced the spark plug and Ignition Module. Same as before.  Engine uses no oil and has about 430 hours on it.  The Cub Cadet Operator's Manual gives no detailed information on troubleshooting.  What should I check?  Thank you.    Frosty

Answer
Frosty
Check the clearance between the coil Check, and if necessary, adjust the magnet to magneto coil spacing using a non-magnetic (preferably) feeler gauge or shim stock (typically .015 inches though some are .005 to .008 inches, see your engine manual).