Leaking Carburettor

[Novamonte]

Hi,

When replacing a dry and leaking fuel hose on by Tricarb BT7 I noticed that fuel also drips from the brass stud next to where the fuel line is attached to the carburettor (see pic). Does anyone have any ideas as to why it is leaking here (and also why there is an unused connection on the carb).

Many thanks!
Clas

 

[steveg]

Those are the overflow connections for that particular carb model. They should have a right-angle hose hanging down from each one.

 

[Novamonte]

Thank you! I also found a reference to that part on Moss' webpage (although it is unavailable). Should I just run the hoses down under the car, and how long should they be? I guess that they should be long enough so as to avoid fuel dripping on the manifold or downpipes...

 

[Patrick67BJ8]

Thank you! I also found a reference to that part on Moss' webpage (although it is unavailable). Should I just run the hoses down under the car, and how long should they be? I guess that they should be long enough so as to avoid fuel dripping on the manifold or downpipes...

Give British Car Specialist a call and see what they have available.

 

[Novamonte]

Thanks! I will try that.

 

[Keith_M]

Steve is correct that these are overflow ports. However, a correctly functioning carb shouldn't overflow. If you've got fuel leaking out it's probably because 1) the float is incorrectly adjusted; 2) the float has sunk; or 3) the needle valve is leaking.

 

[Bob_Spidell]

I ran mine--BJ8--down to the bottom of the chassis rail; affixed by zip tie to the motor mount.

 

[steveg]

I originally used clear fishtank tubing to the bottom of the chassis rail, but it became brittle from the heat. So replaced both drains with brake line tubing, attached to the carb overflows with short lengths of rubber tubing.

 

[Bob_Spidell]

Adding that, on later cars at least, the overflow drain tubes went through a grommeted hole in the heat shield. Looks like your car doesn't have that kind of heat shield, though.

 

[Novamonte]

Here is an update - I checked the leaking carb and found that the needle valve was quite worn, so I replaced all of them and now everything works fine without dripping from the overflow vents. I added clear oil-resistent tubing to these as per Steve's picture, but was unable to find springs that would fit in them, so I put larger springs on the outside of the line instead which do the same job.

 

[Deleted member 21878]

Clas
i was able to find some springs at a local hardware store. i then took a piece of number 12 house wire and cut it to the length of the spring. stripped it to the copper. then i wove it in the spring and after inserting it into the hose, i bent it 90*. the wire holds the spring and the tubing at a right angle.

i did not run mine all the way down under the car. if i decide to do that i will add soft copper tubing to the end of my clear tubes and run them down. Lots of heat down there.

 

[Novamonte]

Thanks! The springs I was able to find were stainless but not small enough to fit in the tube. But it works well, it keeps the tubing from collapsing. If I find smaller springs I might change this. I also did not run the tubing all the way, just far enough to make sure that gas will not leak onto the downpipes or the manifold.
Clas