Small Engines (Lawn Mowers, etc.): Vanguard running on one cylinder only, cylinder head gasket, push tube

Question
I have problems with a Vanguard Model 540000 35hp 2-cylinder. It runs one one cylinder only. Had the spark plugs removed and know its the left cylinder as it does not start running only that cylinder. Got new spark plugs and know checking I can see both spark plugs fire nicely.
Cleaned the carburator as well. No change.
What else can I check?

Answer
Hello Johannes:

Send me the Model and Type or Spec Numbers Off the Engine, Please. Example; 540707-013201. With these I can Locate the Proper Manual and Better Assist you. The Numbers are Usually Stamped Into the Blower Housing above the Sparkplug. If this is an OHV Model Engine, then Check the Valve Clearance and the Cylinder head Gasket. If the Cylinder Head Gasket Blows Between the Cylinder and the Push Tube Galley, the Cylinder will Miss as you Described. 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. Thanks.

Respectfully

John