Fuel Anti Siphon Valve

[bbook83]

In the course of chasing an engine stalling problem on my 1974 Mercruiser 140, I pulled the fuel uptake tube and removed what I assume is the anti siphon valve from the fitting ahead of the fuel line to the fuel pump. In the attached photo, I am depressing the tank side of the spring loaded valve, which pushes the valve open on the fuel pump line side. It seems to move freely when I do that, and presumably can be pulled open by the vacuum of the fuel pump. After reading the technical archives and stickies here, I was expecting a ball type check valve. Should I stick with this one? It is on a 1974 Mercruiser 140.

 

[Bondo]

Ayuh,..... If that one is clear, 'n serviceable, go ahead, 'n use it,....

 

[bbook83]

It seems to work. Just not what I expected. Thanks Bondo.

 

[dubs283]

Suck it with your mouth. The calibration ought to be tested with a known good valve

This is the only method of testing I've ever found reasonable

 

[bbook83]

It failed the suck test, with my uncalibrated mouth, but I don’t know if I can do 5 hg, or whatever a fuel pump does, and this particular valve doesn’t lend itself to the test, so I don’t think I can get a good calibration on something like a ball valve.