Small Engines (Lawn Mowers, etc.): Briggs & Stratton 2BSXS wont stay running, briggs stratton, new spark

Question
The mower will run for 2-3 minutes then die.  After that, you can prime it 10-12 times and maybe get it to turnover once, but that's it.  Without priming, or with minimal priming, it won't do anything.  Relatively new spark plug and air filter, fresh gas and oil was changed last season.  I'm not sure what is actually stopping the engine from running.

Answer
 Hello Scott:

 Remove the Gas Line from the Inlet Port of the Carburetor and Ensure you have the Gas Free Flowing to the Carburetor. If the Gas is Free Flowing to the Carburetor, then the Carburetor needs to be Cleaned and Rebuilt. From you Description it Sounds like the Varnish is Restricting the Gas Flow Inside the Carburetor. Send me the Model, Type and Code Numbers Off of the Engine, Please. With these Numbers I can Locate a Breakdown/IPL of the Engine and Better Assist you. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John