Originally Posted by CHassan

Yeah I would initially suspect the muffler line is plugged or any of the lines are compromised (I've had plug lines after setting a bit with residue in it.)

Next I would inspect the plumbing inside the tank and the tank stopper.

I that fails I guess I would pull the carb apart and look for worn o-rings in the needle valves. and where the carb mounts to the engine case.