Dry fuel line feed from tank--normal?

[Bluedaffy]

Hi forum members. First boat. First post.

Picked up a 1989 20' Stingray cuddy this year. I have two little boys and I thought it would be fun to get something that we could putt around the lake in on nice summer days. We've been having a blast and actually that old 3.7LX Mercruiser has far exceeded my prior expectations in terms of power. It does have a couple little running quirks that I'll need to troubleshoot, but so far my time in the doghouse has been focused on making sure it's set up to be safe.

One of the safety features I read about is the anti-siphon valve. I removed it to check it but found that it was just a regular barb fitting (no valve, just an open hole). As long as I can find a new one in-stock somewhere this should be easy enough to fix. However, something that I thought was a bit odd is when I first removed the gas line nothing came out--not a drip. Wouldn't the vacuum created by the diaphragm in the fuel pump keep gas from draining back into the tank? I'm new to marine engines so I was just hoping to find out if this is normal or if I might have accidentally stumbled over a source of one of the running quirks I mentioned earlier (weak/failing fuel pump?).

Thanks--I appreciate the help

 

[Bondo]

Ayuh,..... Welcome Aboard,...... How long since it'd been run,..??
Dependin' on the lay of the fuel line, it's reasonable that gas dribbled back into the tank,.....

The A/S valve will stop that,.....

 

[Bluedaffy]

Thanks bondo. The boat was run about 2 hours prior to this. Sure, I guess it makes sense that the anti-siphon would also function to keep fuel in the line. I guess I was just curious if under normal conditions a fuel pump would be expected to create a seal that prevents fuel from draining back downstream. Good to learn that this by itself isn't indicative of a problem with the fuel pump.

 

[Baylinerchuck]

It seemed to me at the time when I replaced mine, they were universal. Just need to find the correct thread and barb size.