Ever been concerned with flooding your outboard engine? As of January 2011, the EPA required all portable marine fuel tanks to follow a zero emissions policy. That means they are no longer built as an “open” fuel system (manufactured with a filler cap that vented and released the gas vapor into the air). Attwood Marine came up with a new valve called the Fuel Demand Valve (or FDV) to help ease the flooding worries. The valve was developed to protect engines from fuel being forced back into the system, causing flooding. The FDV installs onto the fuel hose between the fuel tank and primer bulb, and prevents fuel from flowing unless there is demand from the engine. This eliminates excess fuel that would otherwise be forced through the fuel line due to pressure in the tank, and avoids the related flooding and engine failure.