206 Intek B&S 5.5, won't start

Hi,
I am stumped.
I have replaced the carb, there is not an inline filter, checked the plug, has spark and will run for a second on starting fluid.
It was running fine and then I stopped running it and later it would not start.
Any thoughts?
Barry

Pull the fuel line off the carb.
It should flow strongly and be the full diameter of the tube.
If not there is junk in the tank blocking off the fuel supply