Small Engines (Lawn Mowers, etc.): Ariens LM21S with Briggs and Stratton 6.75 Intek, briggs and stratton, fuel stabilizer

Question
I purchased the above unit in 2004 for my mother's modestly sized yard.  It worked okay for 2 years and now runs very rich with terrible power and horrible fuel consumption.  I replaced the plug and sprayed the carburetor with cleaner to no avail.  I see no adjustment whatsoever.  i think I know why Ariens has changed to Kawasaki as I have an old Kubota walk behind that both runs like a champ and has a driveshaft instead of a belt that has slipped off 5 times.   My dealer has since retired and closed his shop.  Alas, I should have bought the Honda.

Answer
Ariens to the best of my knowledge stopped producing mowers. But when it comes to snow blowers they are hard to beat. When did the problem start, has this been since the first time you started it this season? If so did you store it over the winter correctly with fuel stabilizer? If not I can assume it's the carb in need of a rebuild due to the gas turning into varnish in the carburetor. 99% of ALL small engine troubles are the carburetor. But, thats if the obvious has been checked first. Is the air filter clean, is the spark plug new, does the carb have a good flow of gas from the tank? With your statement or poor fuel efficiency I tend to believe you are experiencing a stuck float needle valve in the carb bowl. But can also be a bad float too, shake the float and listen to it as you do, hear fuel sloshing in it? If so it is to heavy to work correctly and flooding the engine..........Tom