Marine Quadrajet Overflow

[76SeaRay]

I have been checking the carb I have which is a newly rebuilt Rochester Quadrajet to make sure it is a marine carb. I can see the seals around the shafts but after reading about the overflow, it does not have a J Tube for float overflow back to the carb. I researched getting a J Tube but no one makes them for the Quadrajet, only the Holley's. Then, I looked closer at the overflow tube on the carb and it appears that it is designed to correctly route any overflow back into the carb. Attached is a picture of the tube. Note that it is slanted towards the carb throat and then it has essentially a wall around the tube so that any overflow gas would have to flow back into the carb. So, I am guessing that this qualifies for a marine carb.

 

[achris]

Does it have a port for a vacuum advance tube? Does it have a fast idle cam with steps? If yes to these questions, it's automotive and should under no circumstances be put on a boat. An Marine carb will also have a port near the top of the primaries for a tube from a mechanical fuel pump to dump fuel into should the pump diaphragm rupture.

Chris...

 

[76SeaRay]

No vacuum advance port and no stepped idle cam. It doesn't have a port (yet) for the overflow tube from the fuel pump so will have to figure that one out.

 

[Lou C]

the marine Q jets do not have a j tube like a holley, but have what you have on yours, there is definitely an overflow tube port for mechanical fuel pump applications.

 

[76SeaRay]

Hmmm, I will have to look again tonight when I get home but didn't see a tube to connect the fuel pump.. Maybe a port there that needs a tube...