Small Engines (Lawn Mowers, etc.): Lawn Mower wont Stay Running, carburetor body, briggs and stratton

Question
I have a lawn mower with a 3.5hp Briggs and Stratton engine. The numbers on the engine are 95902-3107-01 95050352. I've recently put a new primer bulb on it and new spark plug but it still won't stay running. I noticed that the primer bulb takes a while to come back out once it's pushed. Then it will start and run until the fuel is gone from priming. It won't run then until I prime it again. Do you have any idea what could be wrong. Any help is greatly appreciated.
Thanks

Answer
Hello Trevor:

>>From your Description (especially of the Primer Bulb Action) is Sounds like the Carburetor Requires Soaking and Cleaning.
>>You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.outdoordistributors.com/ and Select "Click Here For The Parts Menu". Then Select B. Then Select Briggs. Then Select "Click Here If You Don't Have Your Part Numbers". Now Select the File (using the first 1 or 2 Numbers of your Model Number) for your Model. Select the File 9 at the Bottom of the Page.
>>This can be a Plastic or Metal Carburetor.
>>Once you have the Carburetor Kit for this Unit, Remove the Carburetor from the Tank and make Sure you Clean the Pickup Tube Screen and Blow Out the Pickup Tube with Compressed Air.
>>I Prefer Soaking the Carburetor Body Overnight in Carburetor Cleaning Solution to Properly Clean the Varnish from the Passages Inside the Carburetor Body.
>>Sometimes Spray Carburetor Cleaniers will Work, but Usually Not as Well as Soaking.
>>This Site Addy; http://outdoorpowerinfo.com/repairs/briggs_pulsa-prime_carb.asp Shows you Pictures of this Carburetor and Tank and Describes How to Disassemble this Unit.  
>>If you Hit a Snag or this Does Not Correct the Problem,  I Hope to be Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 3 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. All Follow up Questions are Accepted at Any Time. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John