Hey just installed a rebuild kit for my echo hc1500 hedger, new primer bulb, and fuel filter. After priming I hear like a whining or air leak from the carb, its very faint I have to put my ear up to the air opening with the air cleaner off to hear it. I pulled of the vent and it almost popped off with some gas behind it. Do these echo vent things go bad often? When I try to run it with it off some gas bubbles out of the vent tube. Is this supposed to happen?