Small Engines (Lawn Mowers, etc.): mower wont stay running, oil plug, fuel flow

Question
Hi, I have a cratsman mower.that giving me fits. I had someone look at it three times say results. It will start first pull,run for a few seconds dies. Help My lawn is high.  I change oil, plug, filter every year

Answer
Hi John,

You will need to determine if the problem is a lack of spark or a lack of fuel flow.  Right after it quits, remove the spark plug, reconnect the wire and lay it against the engine head.  Pull the engine over and watch for spark at the plug's electrode.

If good, then try to start it while squirting fuel or starting fluid into the carb intake.  If it starts and you can keep it running by adding fuel, then the carb most likely has dirt, debris or gummed fuel inside.
First, check the gas cap to make sure it is venting and not causing a vacuum in the tank.  If that's okay, you will need to remove the carb, disassemble it, clean all the small internal openings and blow it out with compressed air.   Probe each and every hole with a small wire.   A carb rebuild kit wouldn't hurt either.  

Let me know how you make out.
Michael