[Lynn Eades]

I bought a modern (improved?) needle valve assembly from a Holley carb parts supplier in the USA. I found him on epay, but do not remember who he is.
It works fine btw. Also Ron if you happen to have a vacuum / pressure gauge, try blowing in it. You probably cant move the needle? Does your float arm have a dimple worn into it? Is the pivot pin worn and floppy? If you suspect the valve is sticking, then you need to start suspecting the parts involved. Electric pumps push better than pull, as a general rule. What is your pump delivery pressure?

If you are trying to start from cold (after a time) then you needle valve is likely open already (because the petrol (or some) in the bowl has evaporated) This would mean that there is no resistance to fuel flow and yet your bowl is dry. This might be because the pump is "dry" and wont prime? Maybe you have an air leak on the suction side of the pump?
That should give you a few things to think about?
Not knowing all the details makes distance diagnosis difficult....