Small Engines (Lawn Mowers, etc.): Hunting and surging, adjustment screws, sectional index

Question
John,
I have a DeVilbliss 2300PSI pressure washer w a B&S 6.0HP Quantum engine. The carburetor is new, with only 10 or 12 hours on it. New air filter, new spark plug gapped to 0.30 and new 30W oil. I use only premium fuel in the tank. I ran beautifully (after the new carb installed at the repair shop)for about 10HRS; now the engine is hunting and surging. I cannot see any adjustment screws on the carburetor float bowl (or anywhere else, for that matter). The engine is about 7 or 8 yrs. old with VERY few hourse on it, less than 50. Engine model is 12H812. Any ideas on what to do next? My deck is 3/4s clean and cold weather is coming! Many, many thanks for this invaluable service!

Answer
Hello Mark:

Start the Engine and Using the Choke Lever, Slowly Move the Choke Lever and See if the Surging Clears up. If Yes, then the Carburetor has a Restriction in the Jet. Since this is a New Carburetor you can Usually Disassemble and Use Compressed Air to Blow Out the Trash/Water. The Gas that is Produced Today is Not as Clean as the Gas Produced 20 Years Ago. Water and Trash are a Constant Problem for Lawn Maintenace Companies. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model (5 or 6 Digits) and Type Numbers (first 4 digits Only). Example: XXXXXX-XXXX. Then Double Click on the Model in the Results Area. Select Sectional Index. Now you can Select the Section of the Engine you Wish to View. Please, Do Not Hesitate, If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 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. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John