Small Engines (Lawn Mowers, etc.): B&S 31P777 0296-E1, blown head gasket, twin cylinder engines

Question
I just purchased a sears lawn tractor with this engine. and I want to give it to the grand kids to run around the farm with.  It blows oil back through the carb.  What's the cause, and what's the cure?  Thank You, Dave

Answer
Hello Dave:

On this Model Engine the Problem you Described is Usually Caused by; 1- Over Filled Crankcase Oil. Cure: Drain and Refill Crankcase to Proper Oil Level. 2- The Valve Clearance Requiring Adjustment. Cure: I Do Not Use the Setting Called for by the OEMs. I have Found that the Following Works Best. Remove the Valve Cover (on the Dead Cylinder for Twin Cylinder Engines). Set the Cylinder you are Setting the Valves on to Top Dead Center (Both Rocker Arms will have Play in them when the Engine is at TDC) When Setting the Valve Clearance. Now Loosen the Valve Adjuster Locks and Set the Intake Valve Clearance to .004in -.006in and the Exhaust to .008in - .010in. I have had Better Performance Out of the Mowers and Less Burnt Valves Using these Settings. Be Sure the Piston is at TDC on the Compression Stroke. 3- The Crankcase Breather Requiring Cleaning or Replacing. Cure: Clean or Replace the Crankcase Breather Assembly. 4- A Blown Head Gasket between the Cylinder and the Push Tube Galley. Cure: Replace Head Gasket and Reset Valves. 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: 31P777-0296. Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. 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. Thanks.

Respectfully

John