Small Engines (Lawn Mowers, etc.): murray briggs and stratton 125/102, murray briggs, briggs and stratton

Question
wont start will turn off key has a spark and plenty petrol just wont start stopped to add fuel and just would not start again flush system and added new fuel still no good

Answer
Hello Paul:

Send me the Model Numbers Off the Mower and Engine, Please. With these I can Locate the Proper Manual and Better Assist you. Here is the Diagnostic File for Small Engines. This File will Assist you in Locating the Cause of the Not Start Problem. **Here are some Diagnostic Instructions to Do on the Mower to Locate the Hard/Not Starting Cause. Check the Spark. If Not Firing, then Replace the Plug. If the Plug is Firing, then First, Pour a Small Amount of Gas Into the Carburetor Throat with the Throttle at Full. With the Throttle Still at Full, Try to Start the Engine. If the Engine Starts and Quits, then Remove, Disassemble and Soak the Carburetor Overnight in Carburetor Cleaner (I Use Gunk). I have Found that Most People can Use a Breakdown/IPL and Disassemble the Carburetor Enough for Proper Cleaning. You Only have to Remove the Bowl, Float Pin, Float and Needle Valve and Any Adjustment Screws that Go Into the Carburetor Body. The Welch Plugs Do Not have to be Removed. Then Soak the Carburetor Body and Parts in a 1 Gallon Can of Gunk Carburetor Cleaner Overnight. The Can has a Parts Tray Inside it for the Small Parts. Once the Carburetor and Parts are in the Cleaner, you can Replace the Lid for Safety and to Prevent Accidential Spillage. Then Blow Out the Passages with Compressed Air. Install New Parts if Required. If No Fire at the Plug, then Remove the Coil Shut Off Wire from the Kill Switch at the Engine Stop/Brake Bracket (where the End of the Stop/Brake Cable Attaches at the Engine). Check for Fire. If No Fire, then Remove the Blower Housing and Remove the Ground Wire from the Coil. Check for Fire. If Still No Fire, then the Coil is Bad. If there was No Response from the Engine When the Gas was Poured Into the Carburetor Throat, then Check the Compression.  If this is a OHV Engine, then the Valve Clearance May need to be Reset. 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. 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