Before jumping to conclusions manually test the pump this way. With the pump not mounted to the engine hook up the fuel line from the tank to the pump. Take a spare piece of fuel line and attach it to the outlet nozzle on the pump and the other end into a glass jar. Now holding tightly to the pump, rapidly push down on the actuating arm to work the pump. If the pump is working you should get fuel flowing into the jar. If fuel flows into the jar, remove the outlet line and hook the fuel line to the carb to the pump. Manually pump fuel into the carb. Now with the carb full of fuel, mount the pump on the engine, make sure the actuator arm is under the cam lob. You should feel the arm moving as you install and bolt the pump in place. The engine should now start and run until all fuel is emptied from the carb and the engine will stop. If the engine keeps running, you probably had the pump installed wrong, yes it has been done multiple times by experienced techs. If the engine stops, you are now looking at an internal problem.