Small Engines (Lawn Mowers, etc.): Lawn mower starts then dies., fuel line, lawn mower

Question
hello - my craftsman walk-behind mower starts, runs good for about 3 minutes then dies.  It can't be started for a few minutes, then it fires up right away, only to die again.  I pulled off the fuel line and blew air into it,  didn't seem to be clogged, and checked/cleaned the air filter. I suspect the carb, but am not experienced in repairing them.   Any ideas?  
Thank you very much.

Answer
Hi Rich,

Right after it quits check the spark at the plug's electrode.  If good, then try to start while squirting fuel or starting fluid into the carb intake.  If it starts, then the carb most likely has dirt, debris, gummed fuel or water inside.  You will need to remove the carb, disassemble it, clean all the small internal openings and blow it out with compressed air.

Let me know how you make out.
Michael