Small Engines (Lawn Mowers, etc.): john Deere la 140, briggs and stratton, hp briggs

Question
my john Deere la140 is only firing on one cylinder it is a 23 hp Briggs and stratton i have replaced the plugs because i thought it might be breaking down under power. once in awhile it will run on both cylinders then it will stop running on both cylinders. is it the coil or what do you think it could be. the tractor as 240 hours on it

Answer
Hello George:

>>You can View a Breakdown/IPL of the Engine at this Site Addy; http://www.briggsandstratton.com/maint_repair/manual_and_more/ and Enter the Model Numbers  and the Type Numbers(445577-0121-E1 or 445577-0110-E1) in the Appropriate Box and Click GO. Then Select Download PDF.
>>You can View a Breakdown/IPL of the Engine and Mower at this Site Addy, http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.H... and Enter the Model Numbers and Click Find. Then Select your Model from the Search Results Area. Then Select the Sectional File. Then Select the Section of the Mower you Wish to View Online. *You can Drag the View Windows for Better Viewing.*  
>>According to the Breakdown for this Engine you have 2 Coils under the Blower Housing and it is Possible that 1 Coil is Going Bad or there is a Valve Problem with the 1 Cylinder that is Giving you Problems.
>>The Following is a File I made for this Problem. Any Input is Welcome and Appreciated.
>>If this Engine has 2 Coils, then 1 May be Going Bad or
>>Sometimes the Valve Seat will Loosen and cause the Problem you Described.
>>To Check the Coil/s
>>Remove the Spark Plugs and Wrap the Threaded Section of the Plug with Wire, then Attach the Other End of the Wire to the Engine Block.
>>**First Make Sure the Plastic End that Snaps to the Plug is Allowing Current to the Plug. Use a Test Light or Multimeter and Check for Fire Behind this Connector (through the Large Rubber like Coil Lead to Plug) for Fire to the Plug whenever there is No Fire to the Plug.**
>>Once you are Sure the Coil Lead and Ends to the Plug are Not the Reason for No Fire to the Plug, then with the Plug Still Wired to the Engine and the Coil Lead Attached to the Plug; Remove the Coil Shut Off Wire at the Shut Off Switch.
>>Check for Fire. If No Fire, then Remove the Cut Off Wire from the Coil (removal of the blower housing required) and Check for Fire.  
>>If the Spark Plugs are Firing with the Plugs Out and Properly Grounded to the Engine, then Replace the Plugs and Start the Engine.
>>Operate the Unit until the Cylinder Starts Missing, then
>>Using an Insulated Plug Wire Puller, Pull the Plug Wire from 1 Cylinder. If the Engine Continues to Run, then Replace the Plug Wire and Disconnect the Other Plug Wire.
>>Even if there is No Fire to 1 of the Plugs,
>>Switch the Coils and Start the Engine. If the Dead Cylinder Changes, then
>>Replace the Coil.
>>If the Same Cylinder is Still the 1 that Misses, then
>>Check the Valves and Valve Seats in the Cylinder Head of the Dead Cylinder.
>>If the Engine has 1 Coil with 2 Leads, then
>>If No Fire to 1 of the Plugs,
>>Replace the Coil.
>>If you Hit a Snag or this Does Not Correct the Problem,  I Hope to be Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Be Safe and Happy. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 5 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. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John