Im trying to figure out, and from what i have heard there only on 25OL boats, anyways its the little grey filter, looks like a car gas filter like on a chevy S-10. anyways i need to change it, where can i buy one, and after i do all this gas filter changing, whats the safest way to check for gas leaks? i dont really want to change this filter but i think im gonna have too!

I am guessing you mean the Fuel filter water separator on a mercurser. If so any Boat store. USboat, West Marine type place will have that. Mine is a spin on/off type. When I had a mechanical pump, I like to fill the new filter with new clean fuel before I install the new one. With the electrical I let it the pump do the work.

WIX Filters produces a fuel/water separator with a drain valve on the bottom. Part #33123.