Had a similar issue on our jeep, it would run great but after sometime it would sputter and quit and only after sitting a while would it start up again. We had fuel starvation issues.
We checked the carb and fuel line and filter but never could see any issue. What we found was that a small piece of rubber like debris had balled up and would get sucked into the pickup tube and would block fuel flow, and after time it would settle back to the bottom of the tank. By the time we would check everything the debris had already settled clearing the blockage, it took a while to finally catch it. Maintain a very clean fuel system
