It doesn't look like it from the picture, but I had a muffler pressure problem on a .40 la that had similar but not exact problems as you are having. Set the needle valve like you would to run it, but then take the end of the fuel line and take if off the carb opening (leaving it on the take and remote needle). Now blow through the muffler pressure tap line. Fuel should spill out with minimal pressure, and you should be able to get a small squirt when you blow on the tube hard. You could have a kinked tube(what happened to me), you could have a blocked line to your tank. If you do blow through the pressure line and fuel spills out easily without much hesitation at the begining, then I'm absolutly confused. Let me know and good luck