Small Engines (Lawn Mowers, etc.): Tecumseh Engine Revs up and down, craftsman snow thrower, valve clearance

Question
Hey Eric,

I have a 10 year old Craftsman snow thrower with a Tecumseh engine that starts fine but then revs up and down constantly and backfires sometimes.

I have checked the fuel lines and they're all clear, replaced the carburetor with a brand new one, and it runs exactly the same.

Could it be the governor? Any ideas and procedures would be helpful.  Thanks in advance.....Tom

Answer
I doubt it is the governor but you can use one of the links below, depending on your engine model, to conduct a static governor adjust.

http://www.smallenginesuppliers.com/html/engine-specs/tecumseh/Tecumseh_4-Cycle_

http://www.smallenginesuppliers.com/html/engine-specs/tecumseh/Tecumseh_L-Head_E

I would also check the valve clearance as well.

Let me know what you find.

Eric