Don't get Fueled...

Most built-in fuel tanks have a fuel shut off or anti-siphon valve installed on the fuel tank. It's purpose is to prevent fuel spills in the boat should a fuel leak develop in the fuel system. (other than of the fuel tank itself)
Please note that an anti-siphon valve is not considered a shut off valve. (although it passes CG requirements for recreational power boats)
For additional information concerning CG regulations  on fuel line safety see: http://www.uscgboating.org 

Also, there are situations where both a shut off valve and an anti-siphon valve should be considered. As example, when routing fuel from multiple fuel tanks to a single engine.

The most common problem with an anti-siphon valve is that they can clog with debris, sucked from the fuel tank. If you suspect  a fuel restriction, always check the anti-siphon valve for items stuck in the valve and run the test below.

 

anti-siph.gif (14555 bytes)

anti-siph1.jpg (9001 bytes)

Note that your clear hose goes onto the tank end of the fitting. The anti-siphon's normal fuel flow direction is what needs to be tested. Too tight a valve could cause lean operation of the engine and too loose a valve can allow fuel to escape the fuel tank due to siphoning.
Never try to adjust a faulty anti-siphon valve, toss it and get a new one.

 

Directory  |  Diesel Engine  |  Tools  |
Home Page   |   Returned Mail   |   Odds n Ends    |  Boat Builders  |  Engine Page  |  Electric Page  |  News Page  |  Safety page  |  Trailering  |  More About Us   |   Related Sites   |   Special offers   |   Event Calendar   |   Opportunities