I have a Sierra screw on fuel/water seperater filter on the fuel line of my 1998 225hp Merc. When I went to unscrew the filter to check for water, gas started leaking out when I loosened it a couple of turns. I was wondering how you go about changing these types of filters. Will the gas stop flowing after pressure is released. Anybody that has any experience with these filters please respond this is the first time I've changed one.<br /> Thanks Very Much.