If you have spark, check fuel next. If you can get it to cough after manually priming the carb then you'll need to investigate the fuel system. If the fuel pump has been replaced check the orientation of the fuel lines. If the primary fuel line and the accelerator pump lines have been swapped it will either die off idle or not run at all. A faulty fuel cut solenoid on the carb will kill it as well. If you're not getting any fuel check that the pump is picking up. Does the new pump require a spacer? Is the actuator rod working? How are the fuel filter and lines looking? It'll be something small you've overlooked. Good luck with solving your issue, I doubt it's anything major.