Small Engines (Lawn Mowers, etc.): Lawn vacuum wont start, briggs stratton, lawn vacuum

Question
I have a Briggs & Stratton 4hp model# is 112212-0654. I could not get it started and found old gas in it. The gas was yellowish.  I added acetone to the gas in hopes of removing any gum. The engine did finally start and ran for awhile. Two days later I tried to start it again and it wouldn't run. I tried starting it with starting fluid and it seems like no gas is being taken into the carburator. I checked the pump gasket for tears and there wasn't any. I am not sure what to try next. Any suggestions?  

Answer
Hi, It sounds like the fuel is defently the problem! First drain all the old gas out of it because it is turning to varnish! If you follow the fuel line from the carb down to the gas tank then look inside the tank you will find a fuel filter on the end of the fuel line! you need to replace it. You can get a new fuel filter at your local mower repair shop! Get a good midgrade fuel to put back in it. you might need to take the carb off & clean it with carb cleaner, but try draining the tank & a new filter first. Also get a new spark plug while your at it!
Let me know what happens & we will go from there!
Curt