Small Engines (Lawn Mowers, etc.): B&S twin V one cylinder not working, barrel carburetor, valve action

Question
B&S model 445777 21.5hp Intek type 0172E1 code 010620YG one cylinder not firing. Valve adjustment good Compression 175lb
getting spark. swapped plugs with other cylinder no help. Spark seems to be same for both cylinders thru plugs. Compression on good cylinder 150lbs. Flywheel has not shifted, i.e. key and notch aligned on shaft and flywheel. engine runs on one cylinder. Observed valve action and looks normal.

Answer
Hello Robert:

According to the Breakdown for this Engine, there are 2 Ign Coils. Are you Sure the Coil is Firing the Plug or Did you Just Change the Good Plug Over to the Non Firing Cylinder? It is Possible that the Coil is Not Firing the Plug when the Engine is Running. Remove the Coil Lead from the Plug and Attach it to Another Plug. With the Engine Running, is the Plug Firing? This Engine has a 2 Barrel Carburetor and the Side of the Carburetor that Feeds the Dead Cylinder May have a Restriction and May Not be Feeding the Gas to the Dead Cylinder. Check the Intake Joints for Leaks by Spraying WD40 Around the Joints while the Engine is Running. If the Engine RPMs Level Out and the Cylinder Starts Firing, then the Joint you were Spraying at the Time the Engine Leveled Out is Bad and Requires Replacing. You can View a Breakdown/IPL of the Engine at this Site Addy; http://www.briggsandstratton.com/maint_repair/manual_and_more/doclist.aspx?categ... and Enter the Model Numbers (445777) and the First 4 Type Numbers (0172) in the Appropriate Boxes and Click GO. Then Select Download PDF. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. 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 8pm EST (US). My New Day Starts then. Ratings and Comments are Greatly Appreciated. Thanks.

Respectfully

John