Small Engines (Lawn Mowers, etc.): B&S Blown Head Gasket?, blown head gasket, twin cylinder engines

Question
Hello,

Briggs & Stratton 16 HP Model 28Q777, Type 0662E1 + 697762, rebuilt replacement for my Sabre from a local dealer about a year and a half ago.

Symptoms:  pulsing hiss sound (like maybe air leak), occasional stall with huge cloud of white smoke, plug oil fouled, exhaust shows a little bluish smoke.  Also there's what looks like a spray pattern of accumulated oil
inside the engine cover where it looks like the head joins to the block.

Does this seem like a blown/leaking head gasket?  If so, is there likely to be a root cause or do they just blow on their own?

I've worked on car engines many years ago, but never a small engine like this.  If it's only the gasket, are there other parts which also should be replaced?  Or other things I should be aware of that might not be obvious?

Thank you.

Tedd

Answer
Hello Ted:

Being a Familiar with Car Engines Gives you and Advantage. It would be Similar to a Single Cylinder Car Engine with a Carburetor. 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 and Type Numbers (28Q777-0662). Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. From your Description, it Sounds like the Head Gasket is Blown Between the Cylinder and the Valve Galley and Also to Atmosphere. Usually the Head Gasket is the Only Item to Replace. This is Not a Common Problem, but I Do See it Often. The Head Bolts are Torqued to 220 Inch Pounds (Approx 20 Foot Pounds). Here are the Instructions for Setting the Valve Clearance. 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. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. 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 9pm EST (US). My New Day Starts then. Thanks.

Respectfully

John