Craftsman 6.5 hp Briggs mod 123K02-0267-E1 starts hard dies in seconds

Replaced carb. fuel line primer bulb, new fuel, checked key way, kill switch. Checked and or replaced everything I can think of. Still same issue. If stated enough times it will stay running. Got it running and ran entire tank of gas through it still doesn’t want to start without choking and strangling it.