453 Keeps shuting off

[Bucking Bulls]

I have a 453 with D722 engine runs for awhile then dies. I replaced fuel filter ran for 20 minutes great idling or moving around without a load. started using to move manure out of run in shed keeps stalling or barely runs. Please advise

 

[OldMachinist]

Does it suck the primer bulb flat when it does this? If yes then the pick up line is either clogged at the screen or elbow. Next would be that the tank vent is clogged, try running it with one of the fuel caps loose.
If the primer bulb is fine then the fuel pick up line is likely cracked or broken off and the fuel level is right at that point. If the fuel level is low enough you can remove the right side cap and see the line with a good flashlight.
Fish a wire with a bent hook in there, pull the line out and inspect it.