While I have my 327F+ lifted for access, I thought I may as well change out the pump too. It was an automotive pump, or an old marine pump, not sure. In any case, I thought it would be good to show an image of what the upgraded USCG pump looks like. You can see the failure vent line which is supposed to be routed out of the top of the pump and to the carb, where any overflow leakage will be "wasted" into the carb (rather than into your bilge)



Regards, Paul

Paul,

Silly question, but where exactly does the rupture line connect to on the carb? I think I have a AVS 6117. My original Carter pump did not have the rupture line, and after 45 min or so of searching on the forum and web - no answer except that it goes to the carb. Thanks for your help,

Derek

The new style fuel pumps all have the bypass, as you know, and the stock old style flame arrestors did not have any provision for accepting the bleed off in the event of a diaphragm rupture.

Some of the later model flame arrestors have an attachment on the side to take fumes from the valve covers. A similar fitting is used to upgrade the old flame arrestor and they can be found here at CP Peformance Marine.


http://www.cpperformance.com/products/Fuel_Systems/flame-arrestor-vents.htm


Of course, another method would be to put a hole in the top of the flame arrestor and run a plumbing fitting such as a 90-degree into the top. The idea is to capture the fumes and liquid present in any fuel pump failure at the carb, and suck it into the motor. It is a great safety precaution, and the idea has undoubtedly saved a lot of lives over the years.

Regards,

Paul

Thanks for the info Paul, I need to get one of those fittings.

Derek

Here is the link to the Glen-L Inboard Boat Hardware, a site I frequently like to look through. You can see the new style flame arrestors have the fitting allready installed. This is for crankcase ventilation and/or fuel overflow.



http://www.boatdesigns.com/products.asp?dept=290

Regards,

Paul

Hi Paul,

The fuel pump overflow has to go to the float bowl not the flame arrestor. The Carters didn't have a Provision for this I don't know about the Edelbrock replacements. Rochester Q jets have this provision.


Don Hancock

Hi Don,

I always let people know that because I host the forum, that does not qualify me to have a better opinion than anyone else, and I am NO EXPERT. I'm an enthusiast. You know what that means...........I can be dangerous.

It's my understanding that you can run the fuel pump failure line to the flame arrestor area where it will discharge into the carb. The parts are sold for this purpose, and of course just because they're sold for this purpose does not mean they are USCG approved.

As for the tapping into the float bowl for the line, I would be very reluctant to drill a hole in a carb for this purpose, and would default to the air cleaner system noted, unless this breaks some rule or creates a danger. My OEM Carters don't have any provision for the overflow tube hook up at all, and I would be reluctant to do any drilling. I think I could, however, install something like they furnish on the new Edelbrock, in the event I needed to.

See the photo below, of the new Edelbrock #1409 600. See the fitting they install on these new carbs for this very purpose, it vents into the carb intake right below the flame arrestor, and I think it achieves the same thing as running to the arrestor (but in a neater manner).


Naturally, if you hook to the flame arrestor, you would want to do it in a manner that would not allow fuel to drip down the side of the arrestor and create the very danger you were trying to avoid!

Comments will be appreciated. This is a safety related issue!

Regards,

Paul