Check the fuel filter for plugging as well as the air cleaner and muffler. Make sure the choke control actually opens the butterfly plate in the carburetor when the choke is pushed off. Check the quality of the spark at the plug by laying the removed plug on engine metal (wire on plug) and pull through. The spark should be blue and snappy. Plug gap is 0.020". The insulator should be medium to light tan when the engine runs correctly. If still having problems, check the lower chamber diaphragm in the carburetor for being hard or cracked as it directly controls fuel flow through the carburetor. Hope this helps!