Small Engines (Lawn Mowers, etc.): wheel horse 520, wheel horse, valve clearances

Question
Hello, I have a wheel horse 520 with a 20hp onan engine, when the engine gets hot it doesnt run very well, causing back fire out of muffler when engine throttle is raised,and spitt sputtering would say, when the engine is cold it runs like a champ. Just installed new carb.plugs(.30)plug wires.  Still no change    thanks so much for any advice

Answer
Hello Dennis:

From your Description it Sounds like Depending on the Model; the Valve Clearances Require Setting, the Condenser of the Point Set is Heating up or the Ign Coil going Bad. What is the Compression of the Unit when the Engine is Hot and is Missing and Backfiring. Please, Do Not Hesitate, 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. Comments and Ratings are Greatly Appreciated. Thanks.

Respectfully

John