Small Engines (Lawn Mowers, etc.): continuation of 18 hp briggs & stratton, blown head gasket, overhead valve engine

Question
John, I took the carburator off and cleaned it. Cranked right up and idled fine soon as I open throttle up it starts doing the same thing. Sounds like an old 2 cylinder John Deere tractor motor.I pulled the flywheel and checked the key and even replaced it. Still the same thing. Here are the motor numbers you asked for. Model # 31D777   Type 0233E1   Code 030404ZE    I know with your help we can whip this problem. Could it have damaged the rings or blown a head gasket?  

Answer
 Hello Tony:

 Lets Check the Push Tubes for the Valves. This is an Overhead Valve Engine. Look for Anything like a Bent Push Tube, Loose Rocker Arm, Rocker Arm Not Moving. If this is Working Good, Then Look for a Blown Head Gasket. Go to this Addy http://shop.briggsandstratton.com/BShopProductListingPage.asp?rsvp=0&PARENTID=0&... and Enter the Model Number 31D777 and Typr Number 0233. On the Next Page, Scroll Down to the 2nd Listing and Click on View PDF. This will Download a Breakdown of the Engine. Hope this Helps. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John