Small Engines (Lawn Mowers, etc.): Idle fluctuates up and down, turn the screw, type numbers

Question
Briggs & Sratton 11hp. Mod #258707, Type 0122 01, Code 93020930.
The engine won't idle smoothly. It accelarates up and down and the govenor arm is moving back and forth.

Answer
 Hello Tony:

 You can View a Breakdown of this Engine at this Addy http://shop.briggsandstratton.com/BShopProductListingPage.asp?rsvp=0&PARENTID=0&... and Enter the Model Numbers 258707 and the Type Numbers 0122 and Click Search. Then Scroll Down to the 2nd Listing and Click on the View PDF. This will Download a Breakdown/IPL of this Engine. On Page 4 of 12 you can see the Carburator. Turn the Screw (diagram #94) out 1/4 Turn. If the Idle Doesnt Operate Properly After this Adjustment, then Clean and Rebuild the Carburator. Soak the Carburator Overnight in Cleaning Solution (Gunk carburator cleaner) and then Blow Out the Passages with Compressed Air. Install New Kit. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John