Small Engines (Lawn Mowers, etc.): No spark to the plug, good hope, flywheel

Question
OK , to start off with my murray 13.5 hp riding mower model number 40500098. Well before the end of the year last year, the mower would not fire at all, but when i would unplug the ground going to the coil, it would then fire and run until the fuel ran out of the carb... i bought a new coil, thinking that was the problem.. it worked fine for maybe 2 days, then did the same thing again, and now it wont even start when the ground wire at the coil is unplugged.. i've racked my brain on this all winter.. checked every possible switch i could find, all of them checked out ok...  Maybe i got ahold of a bad coil again? if so what could be causing these to go bad.. i've checked the wiring for any damage and dindt find anything.. the starter still turns over fine and all.. is there anyway to bypass everything or a way to test the coil ? im so frustrated with this i'm considering buying some dynamite.. lol help

Answer
 Hello Mark:

 LOL  Now you See just a Minute Part of What I went through for 30yrs. LOL  Anyway, If you have the Shutoff Wire Disconnected and No Fire, then this Coil is Bad. Is this the 2nd or 3rd Coil for this Engine? I have Purchased Coils for Some Time and Finding a Bad Coil is Not has Rare as you Would think. Most Times you will have to Replace the Coil Twice During the Life of a Mower Engine. Once when you Replace the Original Coil and Once When you Replace the Bad Coil you Just Bought. You got Lucky. This Coil went Bad before the Warranty went Out. The Only thing that will Cause a Coil to Burn Out Quickly is a Weak Magnet on the Flywheel. If the Magnet will Hold a 9/16 Combo Wrench then it is Good. Hope this Helps. I am here if you Require more Assistance. Thanks.

 Good Luck

 Respectfully

 John