Re: old evinrude 6 hp
It sounds as though it is flooding because the float needle valve is not seating and shutting off the fuel flow when the bowl is full.
Could be dirt, wear, not fitted properly, defective or incorrectly adjusted float but that's the area I would look at to begin with.
As an experiment after filling the bowl with the primer bulb disconnect the fuel line and try to get it started, persist if necessary. If I am right once you get it going it should run until the bowl is nearly empty.
BTW look at TD's "Top Secret File" pinned second item from the top of the Johnson & Evinrude Index.
You'll find several topics there that may be of use to you