Did I? I must be older than I thought coz I can't remember doing that ya dad changed the fuel pump. It could still be the fuel pump as I think pongo put another second hand one on It could be the fuel line coming out of the tank that's pulling air in like Tom said.
is there a fuel filter on it(i can't remember)?

Yeh theres a fuel filter, got another fuel pump at weekend so will fit it when i can.

Have you tried removing the fuel cap, planting your lips in t'spout, and blowing gently? This might highlight any perishing pipe problems or leaks (you may need someone else to slip under the car and listen/look carefully).

try putting petrol in the tank first, think simple

Yep. If you've put a gallon in, then you know there's some fuel in there. Also try sloshing a bit into the top of the carb and see if it will fire then. Just be careful not to get petrol absolutely everywhere.