Small Engines (Lawn Mowers, etc.): Mower dies after about 30 seconds, minute job, float bowl

Question
I have a B$S mower model 10A902 and have had a recurring problem in which the engine starts OK after I prime it with 3 pushes on the bulb but the engine dies about 30 seconds later. I followed the owners manual for this problem by cleaning the air filter, cleaning debris, and trying fresh fuel with an additive but the problem continues. Last couple times this happend I took it to a local shop and a week later is was fixed but the question I have is surely this is some pretty easy fix that I could probably do myself and save the money and aggrivation of always having to take it to a shop every time this happens.I'm never able to talk to the person who fixes it at the shop but the lady at the counter mentioned that it was something with the carburator. Any suggestions on what could be causing this?

Answer
Dirty carburetor.  You can try draining the carburetor bowl by removing the float bowl nut on the bottom of the carburetor.

This link if for Tecumseh carburetors but your Briggs is very similar.  The most common problem that your described is a dirty carb.  

Remove, dis-assemble and clean the carburetor with compressed and carburetor cleaner and you should solve the problem.  About 45 minute job.

Try just removing the bowl nut to drain the carb first.
Let me know what happens.
Eric