Small Engines (Lawn Mowers, etc.): fuel problem on Briggs engine, twin cylinder engines, valve clearance

Question
I'd appreciate your help.  My Briggs is an 18.5 hp on a 2005 Troy-Bilt riding mower.  The model is 31P700-770293 type 029E31 code 031103ZE, and the carburetor brand is Walbro.

The engine wouldn't start one day after two years of reliable service.  The engine wasn't getting fuel, so I cleaned out the fuel lines, replaced the fuel filter, and eventually cleaned and rebuilt the carb with a kit. I have not replaced the solenoid.

It seems to be a problem pulling gas from the carb. I can put fuel into the carb and it starts and runs.  If I put my fingers over the air intake and make the suction stronger the engine will run indefinitely.  But take away my hand and it stalls immediately.

I feel like it's a simple solution I'm overlooking.  Can you help me?

Answer
Hello Lou:

If you Did Not Soak the Carburetor Overnight in Carburetor Cleaner or Check the Fuel Shut Off Solenoid, then the Carburetor can Still be the Cause of the Problem. Remove the Carburetor Solenoid and Go to the Hardware Store. Purchase a Bolt of the Same Diameter and Threads. It Needs to be 3/4" Long. Put this Bolt in Place of the Solenoid. If this Corrects the Engine Problem, then Replace the Solenoid. ***NOTE: THIS IS FOR CHECKING THE SOLENOID ONLY I NEVER SUGGEST YOU OPERATE THE ENGINE WITH THE SOLENOID OUT OF THE CARBURETOR EXCEPT FOR TESTING PURPOSES*** Sometimes the Plunger is Moving, Just Not Far Enough to Allow the Gas to Enter the Jets. The Valve Clearance can Also Cause this Problem. Setting the Valve Clearance is as Follows; 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 .003in -.005in and the Exhaust to .008in - .010in. I have had Better Performance Out of the Mowers and Less Burnt Valves Using these Settings. I Suggest you Check the Solenoid Cut Off Solenoid First, then Re-Clean the Carburetor if it was Not Soaked and Cleaned. Then Do the Valves if Required. Hope this Helps. I am Here if You Require More Assistance. Let me Know What Happens, Please. Thanks.

Good Luck

Respectfully

John

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Respectfully

John