Kohler KT745 pulse pump issue

I have a KT745 26HP engine which I did a basic tune up on. It was running fine previously. Changed the air, fuel and oil filters. Replaced the spark plugs and fuel pump. Drained oil and replaced with a little less than 2 quarts. The engine started back up, ran as normal for perhaps 10 seconds, then shut down. There was no fuel in the fuel filter. I confirmed that the line from the tank to the filter was clear. Assuming that the new fuel pump might be defective, I reinstalled the old pump and still no fuel flow. Reinstalled the old fuel filter, just in case, but no effect. I checked the pulse pump hose from the valve cover and could barely detect any positive or negative pressure. It seems like there isn't enough air being moved through the pulse pump hose to drive the pump. Any suggestions? Thank you in advance.
UPDATE: Problem solved. I removed the pulse pump hose from the valve cover and found that there was plenty of pressure/suction at the valve cover port. The hose, however, was severely restricted. Turned out that the new fuel pump, unlike others I have previously installed, had a small black rubber cap on the connection for the pump hose. I didn't notice it when I connected the pulse hose to the pump, so it became lodged in the pulse hose, remaining there when I disconnected/reconnected the hose. Removed the rubber cap from the hose and all is well.