Small Engines (Lawn Mowers, etc.): Will only run on one cylinder, briggs and stratton, tractor model

Question
John,

I have a Craftsmen garden tractor model 917.255920 with a B&S engine model 422707-1211.  The engine will only run on one cylinder and stalls under any type of load.  The carburator has been rebuilt and the armature has been replaced with no improvement.  Engine can be difficult to start once it stalls.  The motor will backfire when starting if the choke is completely open.

Thanks for your help.

Mark

Answer
 Hello Mark:

 You can View a Breakdown of this Engine at this Addy http://www.outdoordistributors.com/ and Click the B. Then Select Briggs and Stratton. Then Select Dont have Part Numbers. Then Scroll Down to the File #42 and Click. Then Scroll Down to the 422700 Folder and Click. This will Download a Breakdown of the Engine for you to Wiew Online. Is the Spark Plug Firing on the Dead Cylinder? If Yes, then Check the Compression in the Non-Firing Cylinder. From your Description it Sounds like a Bad Coil/Ignition Module or a Blown Headgasket or a Valve Problem. Most times it will be a Headgasket. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. I enjoy knowing the Outcome. Thanks.

 Good Luck

 Respectfully

 John