I have a 2000 sportsman 500. I can't seem to get a pulse from the carb to work the fuel pump. I can blow into the fuel pulse line and get fuel to pump out. Also did a vacuum check on the pump and it looked good. It seems like the carb is not pulsing the pump. I started it up using a squeze ball to pump fuel. I put a vacuum gage on the carb but got no reading. It's a new carb. How does the carb get it's vacuum.