My B has sat for a couple years and I was trying to get it going yesterday. The fuel smelled bad, so I drained it and put in new. It wasn't starting, so I tested the spark and had fire. Then I gave it a couple squirts of starting fluid and it finally did start and it would run ok only with the choke wide open. After several minutes it was sputtering so I closed the choke part way and it ran for a while. Probably 10 minutes or so total. Finally it sputtered and quit and it wouldn't start again. Is this likely a carb issue? What should I do next to try to get this thing to start and run? Thanks to any suggestions!