Small Engines (Lawn Mowers, etc.): mower wont stay running, briggs stratton, carburetor

Question
I have a 5hp briggs&stratton push mower. It starts right up but will not stay running unless you keep pushing the prime bulb. Any suggestions to what the problem may be?

Answer
You have a carburetor that's in need of cleaning.  If this has the carb mounted on the tank, the diaphragm and gasket between the tank needs to be replaced.  Also pay attention to the intake maniflod where it comes past the starter housing.  The plastic ones will sometimes have a hole worn in them.