Small Engines (Lawn Mowers, etc.): Lawn Mower Wont Stay On, briggs stratton engine, briggs stratton

Question
Murry Push Mower with Briggs & Stratton engine was being used... last week it was revving up and down like it was going to die, but then would stay on, so I knew trouble was brewing.  This week I started to mow and it started just fine, but after a short time on cut out.  I started it up just fine, this time it only stayed on for a few seconds.  It starts again and again on the first pull without needing to get primed, but just won't stay on.

Thanks!

Answer
Hi Rob,

First, check the gas cap to make sure it is venting and not causing a vacuum in the tank.
I suspect a sticky float or a piece of dirt blocking the fuel flow.  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.   Adding a carb rebuild kit wouldn't hurt either.  

Let me know how you make out.
Michael