Small Engines (Lawn Mowers, etc.): B&S 3.75 wont stay running, carburetor, gunk

Question
B&S 3.75HP Model:9L902 Type:0305 E1 Code:06012552
This mower is fairly new.  I ran just fine, and then it started revving and would cut off, but I was able to restart it.  Now it won't stay running at all.  It starts, putts, then dies.  I have cleaned the air filter, checked the spark plug (which it shouldn't even crank at all if it was that), and I have tried to adjust the throttle springs.  My son did leave it out in the rain at one point, but I poured out the rest of the gas that was in there and refilled it.  Any suggestions would be greatly appreciated!  I am a mechanic, and was a humvee mechanic in the Army, so I feel absolutely DUMB for this little engine kicking my butt!
Thanks for your help
Shawneen

Answer
Hello Shawneen:

From your Description, it Sounds Like you Need to Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I use Gunk). Then Blow Out the Passages with Compressed Air. Install a New Kit if Required. From Viewing the Breakdown/IPL, I see this is Possibly the Plastic Carburetor. There are No Adjustments and this Carburetor Must Be Clean in Order to Function Properly. You can View a Breakdown/IPL of the Engine at this Site Addy, http://www.ordertree.com/index.asp and Scroll Down. Select the Manufacturer and Enter the Model Numbers (9L902) and Click Go. Then Select your Model from the List Provided. Then Double Click on the Model in the Results Area. Hope this Helps. I am Here if You Require More Assistance. Let Me Know What Happens, Please. Thanks.

Good Luck

Respectfully  

John