Hi, so I've been working on my 72 CB750 for a few weeks now. Cleaned the carbs and tried to start her up. The starter worked but it did not fire up. It seemed like it wasn't getting gas. I took the Petcock off and cleaned it all out and still nothing. When there is gas in the tank and the fuel lines are disconnected should fuel come out when the fuel Petcock switch is ON? Because nothing is coming out.