Small Engines (Lawn Mowers, etc.): Riding Mower stalling, briggs stratton, gas tank

Question
I have a Poulan Pro Mower with a 20hp Briggs & Stratton Intek V-twin engine.  It has been run for 3 seasons.  Now it will run for a short period of time, then it will shut down.  If allowed to sit, it will start again for a while before shutting down again.  I have drained and cleaned the gas tank, replaced the fuel filter and the fuel pump.  Nothing has helped.  I would appreciate any suggestions.  Thank you.

Answer
Hi Crystal,

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.  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.  Check the gas cap to make sure it is venting and not causing a vacuum in the tank.

Let me know how you make out.
Michael