vacume pipes?????

hi.my 1989 clipper keeps cutting out after a mile or two, lets it settle then goes for same distance.could it b sucking in to much air.some of the vacume pipes are missing from the green ball to the weber carb i have had fitted. or could it b the rubber gasket under carb?????

could be air lock in tank.
could be over fueling.
could be coil failing.
could be choking itself (assume manual choke with wber conversion) i.e. choke flap not closing
vacuum pipes is unlikely as the weber isn't as sensitive to issues with it (and it's doesn't need the vac res anyway)

could be a weak fuel pump ---or bloked fuel filter-----------------crap in tank---------

o.k thanks people.will check over these things.