Carter B&B 1 Float bowl vent

[OUTFXD]

Filled the car..  After driving her I noticed a potent gas fume smell.

 

Pulled over and popped the hood, The bottom of the carb was coated in fuel.

 

Pulled the carb apart  worked the throttle linkage and nothing,  Put the carb back together work the throttle and it starts leaking out the Accelerator pump linkage opening. 

 

Thought  occurred to me the float bowl was getting pressurized.  First stop,  float Fuel bowl vent. 

 

After tearing the carb down.  The only thing that looked like a vent,  didnt go to the float bowl. It went to the space that holds the Accelerator pump discharge nozzle,  and didnt have any obvious connection to the float bowl

 

What am I missing?

[Sam Buchanan]

[Ivan_B]

Do you have a picture of the actual carb, showing where it is leaking from? It sounds like your bowl is simply over the top, again... Happened to me, recently

[OUTFXD]

I'll try to get a pic tomorrow.  Ironically,  the leak is more prevalent when the fuel in lower in the bowl...

[Ivan_B]

How do you know, did you took your float down a notch? That does not necessarily mean that the fuel is lower in the bowl, not at all

These carbs do not have a drain plug, so we cannot see the actual fuel level during operation, unfortunately. I also adjusted my float to be lower, put everything back together, and then the carb started leaking even worse. The problem was not float/level related at all, the bowl needle just wasn't closing.

Edited September 2, 2023 by Ivan_B

[OUTFXD]

Went out this morning.  Let the car turn over a few times.  I have to admit I was encouraging the engine to flood.  Looked under the hood and fuel was just cascading down the manifold! 

 

Took a couple pics.  #1  view from the engine compartment  #2 Fuel level in the float bowl.  #3  opening that fuel is leaking through.

[Ivan_B]

Ha, it is simply leaking over the acceleration pump inlet. I am 100% positive, you are overflowing just like I was, a few weeks ago. Take the seat and the needle out and inspect them for proper operation. Also, check your float, to make sure it actually floats and has no gas splashing inside

 

If you really want to test this out: take the plugs out, disconnect the ignition coil, and ask someone to crank the engine with the carb cover removed, and see what happens.

Edited September 2, 2023 by Ivan_B

[OUTFXD]

Needle and seat are new,  Float works fine.  I must  have the float level messed up. 

 

Well.  Back at it.  Thanks for the advice!

 

[Ivan_B]

Well, if you believe that the level should be correct, the aforementioned test will pressurize the system. If everything is working as it should, the fuel flow should stop as soon as the float is up. Just like in your toilet ? Alternatively, the gas will go over the edge and leak out of the accelerator pump lever because that is the lowest exit point on an assembled carb.

Make sure to put some rugs around the carb, while testing

[Sniper]

The bowl vent is the well the accelerator pump link occupies.

[OUTFXD]

Went out this morning. checked the bolts and nuts.   Cranked her over till the float closed the needle and seat.  Fired her up and let her idle for 10 15 secconds  with the top of the carb removed.  got out and checked.,  No leak.   Turned the engine off.  Put the top on the carb,  Fired her up, IMMEDIATELY  gas starts cascading  out from under the float bowl.  

 

So... Between top on and top off.  something changed.  

 

Suggestions?

[Ivan_B]

How's the float pin clip doing? When you put the top on, it should press the clip down to hold the float pin in place. If you press the clip down with your finger, is the float still moving? ?

[OUTFXD]

The float should move around the pin,  I'll check and get back to you.  I took the carb apart  several months ago and there was no Pin clip at all so I home built one.  it could easily  be to big/small/fat/out of shape....

 

[OUTFXD]

Check the Pin clip.  I noticed when I put pressure on it it changed the float height.  Also noticed that when It was under pressure The float would move down with the fuel.  But would not move back up to shut the needle and seat.   A coupe light whacks with a hammer to "shorten" the Float pin clip and everything seems to be in working order.

 

Thank you all, special kudos to Ivan_B , sniper and Sam Buchanan for helping me out!

[OUTFXD]

So... This was the very definition of Quantum Physics.  The result changes depending on weather or not you can observe what is happening...

[Ivan_B]

What are you talking about? Is it leaking again? ?

[OUTFXD]

nope nope,  That was meant to be said in the past tense.   The float would work if I took the top off the carb and looked at it,  if I put the top on the carb the float wouldnt work.     The result changed depending on weather or not you where observing it.   This was meant as a joke.

[soth122003]

That is one of my very favorite theories, if you can't see things you don't know what is/is not working. Carb top off, carb works. Carb top on, it doesn't. Why? You don't know because you can't see the operation of the float. It's not a true theory of Quantum Physics but it is an interesting parallel.

 

In Schrödinger's original formulation, a cat, a flask of poison, and a radioactive source are placed in a sealed box. If an internal monitor (e.g. a Geiger counter) detects radioactivity (i.e. a single atom decaying), the flask is shattered, releasing the poison, which kills the cat. The Copenhagen interpretation implies that, after a while, the cat is simultaneously alive and dead. Yet, when one looks in the box, one sees the cat either alive or dead, not both alive and dead. This poses the question of when exactly quantum superposition ends and reality resolves into one possibility or the other.

 

In other words you can't tell until you open the box, or in this case the carb.

 

Joe Lee

 

[Sniper]

1 hour ago, soth122003 said:

Carb top off, carb works. Carb top on, it doesn't. Why?

 

Simple, the top holds the float retainer in place, evidently there is an issue with that retainer.  Bet if you pressed it down so that the retainer was even with the bowl top you'd see an issue.  Looking at that retainer in the OP's pic, it is in sad shape.

 

A new one

 

https://www.carburetor-parts.com/retainer-85-801

 

I would also recheck and double check the drop and closed settings of the float, with the retainer in the proper place.  Carefully note how Carter has you check the float for level side to side as well as distance from the bowl top.

 

Here's a link to the Carter manual on servicing these carbs.

 

 

Edited September 6, 2023 by Sniper

[Ivan_B]

5 hours ago, OUTFXD said:

The float would work if I took the top off the carb and looked at it,  if I put the top on the carb the float wouldnt work.

These are just the usual little car "mysteries", nothing extraordinary about them; usually explained by the laws of physics and thickness of one's fingers ?

For example, I dropped a screw into the engine bay, the other day, and could not find where it went. Ordered a flexible magnet but still could not find it. The thing just disappeared. Then, being a practical DIY'er, I dropped an approximately the same screw from an approximately the same location to see where it goes. On the third attempt, it bounced of the engine block and landed inside the frame rail, on the opposite side to where it was dropped from. Found my missing screw in there as well.

 

I like them carbs with a sight-glass in the bowl. I might even put one into the B&B when I have nothing else to do