Small Engines (Lawn Mowers, etc.): B&S Troybuilt riding mower 17.5 h, flat tire, spark plug

Question
I hit something mowing and ended up with a flat tire and the motor started making a different sound so i turned it off.  It will crank but it won't stay running.  I removed the spark plug and checked the compression and that seems fine.  It seems to have idling power and spits and sputters.  Does it have anything to do with the exhaust. I belive it has a cadalic converter on it.  Oh yeah the ground was wet when i was mowing.

Answer
 Hello Nova:

 Check the Flywheel Key. This Usually is the Cause when Something is Hit. If you need Instructions on Removing the Flywheel and Checking the Key, just let me know. Hope this Helps. Let me know what Happens, Please.

 Good Luck

 Respectfully

 John