Slant 6 wont start

thats pretty classic signs of not getting fuel... it runs on the starting fluid and then runs out...

as said make sure your getting fuel out of the carb...

before trying to start it did you crank it a couple of times for about a minute? all the fuel could have drain to the tank...

or

the diaphragm in the pump is bad

or

you have a clogged fuel filter