In Reply to: Sputtering 9n posted by Michael K. on May 26, 2018 at 22:57:04:
Certainly old gasoline will affect their operation. As I recall it does require turning the large screw out. Do you have room to add fresh gasoline to dilute it?
The second thing I would be suspicious of would be a vacuum leak. Take a bottle of propane or some spray carb cleaner. With the engine running spray around the manifold and the carburetor. Particularly around the throttle rod. If you find a area where the engine speeds up, you have found a leak.
Once you have checked these out (and corrected) you may find it adjusts.