Small Engines (Lawn Mowers, etc.): Engine Dying, briggs and stratton, riding lawnmower

Question
I have a 4 year old Craftsmen riding lawnmower with a Briggs and Stratton engine. I will crank and run fine for 15-20 minutes and die. After sitting for awhile it will crank and run for about the same amount of time. I have changed the spark plug, fuel filter, air filter, cleaned the gas tank, and checked the gas cap for venting. Everything seems to be great when it is running. What do you suggest?

Answer
Hello Gary:

The Following is an Instruction File I Made for Checking and Repairing this Problem. Run the Engine Until it Quits, then Remove the Spark Plug. Wrap a Wire Around the Threads and Attach the Other End of the Wire to the Engine Block Turn the Engine and See if the Plug Fires. If No, then Disconnect the Shut Off Wire  at the Control Bracket First, Check for Fire at the Plug. If Still No Fire at the Plug; Then Disconnect the Shut Off Wire at the Coil (usually requires removal of the blower housing) and Check for Fire at the Plug. If No Fire at the Plug , then the Coil/Ign Module is Bad. The Coil/Ign Module to Flywheel Gap is .020in. On Some Model JD Engines, there is a Igniter that Goes Bad and Not the Coil. The Igniter is the Same as an Ignition Module. If the Plug Fires at Anytime During these 2 Checks, then a Safety Switch or Wire May be the Problem. Yes the Engine will Turn Even with a Bad Safety Switch. The Blade Safety is Usually the Cause of this. The Starter Turns and The Engine Doesn't Fire is an Indication of a Bad Coil/Ign Module or a Faulty Blade Safety Switch. The Clutch Safety Prevents the Starter from Engaging so the Mower Does Not Move when the Starter Turns the Engine. The Seat Safety is Designed to Stop the Engine if the Blades are Engaged or the Clutch Safety is Not Engaged when you Leave the Seat. To View a Breakdown of this Unit Go to this Site Addy, http://www.searspartsdirect.com/partsdirect/index.action and Enter the Model Numbers and Click Search. From this Page you can View Diagrams and Parts Lists for you Equipment Using the "View Sub Components" Section. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John