Fuel pump not priming

Always. I double checked.
But I got it to run kinda. I took the fuel line off and primed it to see if an adequate amount of fuel was coming out. When I did that I lifted the tank back and then decided to start. It ran and I let it idle for about 5 min. Then went to give it gas and it died. I can’t get it to cranks again. I guess I’m gonna take it apart again and check the fuel pump assembly again.
I did notice I don’t have a rubber o ring on the diagram. #7. It wasn’t there when I took it apart