That's it, I unscrewed that and pumped up and down and when vent plug on pump is open it squirts out but some does come out the plunger itselfOn mine, the lift pump is where the t-shaped handle is in the photo (although mine has a question-mark shaped handle which you unscrew, then pump up and down to prime. )
Was thinking about putting in an electric pump to feed fuel in from tank to see if that helps
But don't really want to cut original steel pipe to fit it in