Small Engines (Lawn Mowers, etc.): Lawn Mower dies, bad hope, coil ignition

Question
I have a Craftsman Rotary Lawnmower 6.5 HP approx. 4 years old.  It stopped while mowing and wouldn't restart.  I replaced the spark plug, blade, filter, changed oil and drained the gas and bought new gas.  It started right up but then died out again after about 20 minutes of mowing and wouldn't start back up.  After sitting for about 45 mins it started back up.  What could be the problem?

Answer
 Hello Travis:

 From what you Described, it could be the Coil/Ignition Module or a Bad Gas Tank Cap. Check the Gas Tank Cap and Ensure it is Venting the Tank Properly. When the Mower Quits, Check or Spark at the Plug Right Then. If there is No Fire at the Plug, then the Coil/Ignition Module is Bad. Hope this Helps. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John