[Destroyer]

Mannydvk11, I did a little research and found out what that grey thing is. As I suspected, it's a pressure regulation device. It's called a "Fuel Demand Valve". You can find out all about it at the following link:

http://www.mercurymarine.com/parts-a...e-fuel-system/

Please notice that in the description it clearly states that it's to prevent fuel from a pressurized tank entering an engine and creating a fire hazard. What isn't stated is that the pressurized tank is being mandated by the EPA (Extremely Pathetic A$$holes) to prevent fuel vapor from entering the atmosphere. (Even though pressurized tanks create a fire hazard). In other words, it's something that we could have lived without but is being forced down our throats by an overzealous government agency. So instead of the simple, cheap two-way vent (a sealable hole) that used to be on portable tanks, now there's an expensive one way valve that only allows air into the tank, but will not release vapor out, (thereby causing the tank to become pressurized as the warmed fuel expands) and a fuel demand valve system. And of course, it ain't free. If anyone has noticed the outrageous price of portable plastic gas tanks lately it's because they all must use a special plastic now so that Ethanol doesn't effect them. Just another little cost/tax being forced on us by big brother. But I digress... the grey thing is as I described it previously, a safety device.