When Mr. Pete said to check the pilot jet, from your reply I did not get the feeling you truly understood which jet he meant. It is not one of the jets accessible thru the float bowl. Please excuse me if you did understand which jet. I in no way mean to talk down to you. Just making sure.
I found the picture on line and think it is the best I've seen to explain the pilot jet and help understand how it could get plugged and no amount of soaking or spraying will open it back up, something I learned here on this site, probably from Mr. Pete.
The pilot jet is the tiny little brass insert to the left of the air screw and to the immediate left of that tiny pocket in the center of the airway.