Small Engines (Lawn Mowers, etc.): Patriots Forester Shredder engine does not start, air filter element, shiny surfaces

Question
I have a Patriot's Forester Shredder/Chipper model#: T9900301; Serial#: 14523. I think the engine is Tecumseh 10HP HM-100. I t was working last year, but stopped in the last run-maybe overheated or big piece blocked..I am not sure. Then, this year, when I try to start, it doesn't. I can pull the rope and the rotor rotates, but it does not start the engine. Oil level is near max. so this should be ok. I checked the spark plug. It was black, so I lightly filed to expose shiny surfaces, but it did not make any difference. There is some gas in the tank, not full though. Should I fill the tank? Or do you see any other cause of this problem?

Answer
It sounds like the fuel in the tank was left there from last season.  As old gas evaporates and leaves of residue in the tank and in the carburetor.  This will have to be cleaned.  Remove the tank and clean out the old gas.  If you have a fuel filter change it and be sure your fuel line is not blocked.  Next remove the carburetor and disassemble it.  Be sure to get out the main nozzle that goes up into the Venturi of the carburetor.  Use a wire from a twist tie to clean all the air and fuel passages.  Purchase our carburetor kit and new mounting gaskets from your dealer and install.  Note the carburetor using the new gaskets and put fresh fuel in the tank.  Be sure to put a new air filter element in the engine also.  If the oil in crankcase is from last year change it.  I think this will take care of your problem.