Carter BB-1 fuel leak

[GaryBudd]

Been awhile but started the 29'DeSoto K today.I now have gas leaking from bottom of carb. Doesn't appear to be stuck float.Could this be caused from my electric fuel pump? It is a low pressure 6 volt.If so can someone suggest a fuel pressure valve for me. I have enclosed a photo of my carb . At idle no leak but as I rev it up it leaks more.

[Guest]

If it doesn't leak at an idle I don't think it is too much pressure.  With an electric pump the pressure is constant no matter the speed of the engine.  When the engine is rev'd up the pressure from the pump is the same so if you then have a leak it must be internal in the carb.

[Taylormade]

Is it a constant leak once the revs go up?  These updraft carbs have a small opening at the bottom to allow accumulated gas to drain out when you shut the car off.  Is this where the gas is coming from?  Or, have you located the source of the leak?  You say the bottom, but can you tell where on the bottom?

[maok]

6 hours ago, Tinindian said:

If it doesn't leak at an idle I don't think it is too much pressure.  With an electric pump the pressure is constant no matter the speed of the engine.  When the engine is rev'd up the pressure from the pump is the same so if you then have a leak it must be internal in the carb.

Yes, agreed.

Also, if it was a high pressure issue, it would be leaking from the vent hole and/or the pump rod entry and out the main jet down the throat. 

 

But a pressure regulator would be a good idea. I use one of these;

 

http://www.ebay.com.au/itm/Speco-Meter-FUEL-PRESSURE-REGULATOR-1-6-PSI-512-00-AUS-WARRANTY-/131932272533

[GaryBudd]

Yesterday after car had not been started for 2 days with throttle closed no leaks,I pushed to full open and leak started again.I have enclosed a photo of spot where gas is coming from. I sent this carb out for rebuild and I am Leary of opening it up and causing more problems.Any ideas ? I have a low pressure fuel pump installed. Red arrow shows where gas is leaking.

[thehandleman]

two things cause my bb1 to leak underneath to much fuel by either closing the choke plate and kicking the accel pedal two many times,if you have the brass accelerator plunger it will throw a bunch of fuel up also the float set to high will flood it when mine is running there is no better then a BB1 but takes very little to throw it into the peeing flow mode, try no elec pump on, and no choke closed, just one pump and motor good luck this is just my experiences

[maok]

Perfectly normal for excess fuel to flow out from there when attempting to start.  I hope you don't have your exhaust passing under the carb. Not long ago the carbking explained that you can thread a pipe to feed back up the carb to feed the excess fuel.

[maok]

Here is Carbkings explanation, lot better than mine;

 

Quote

When the engine is turned off, with an updraft carburetor, all fuel currently in suspension in the intake manifold will fall (gravity) to the throttle plate, and then into the air intake of the carburetor. To counteract this issue, Carter offered a "drip tube". There is a threaded boss in the lowest point of the air intake with a tiny hole. All of the gasoline falling into the air intake will congregate just above the hole. The drip tube was a piece of copper tubing connected on one end to the threaded hole in the intake, then dropping a couple of inches, sometimes making a loop for more volume, and finally connecting to the threaded hole in question in the picture, which is above the throttle plate and exposed to engine vacuum. When the engine Is turned off, the fuel will accumulate in the drip tube. When the engine is started, the fuel in the drip tube is pulled into the intake, and acts as a "starter circuit" instead of the physical choke. Fuel leakage is not a desirable trait on a boat, and the drop tube pretty well solved the issue!

 

[GaryBudd]

7 hours ago, maok said:

Here is Carbkings explanation, lot better than mine;

 

 

My concern is the fact the exhaust does run under carb. If possible could someone post a photo of carbkings solution?

[thehandleman]

my exhaust runs under also on both my silver domes 

[thehandleman]

i found a bb1 with this mod on it here is pics

[GaryBudd]

Thank you so much.I will build this tomorrow.

[thehandleman]

GOOD LUCK!!!!!! SEND ME A PICTURE OF YOUR CAR NEED ANY PARTS???

[keiser31]

Thanks for sharing those photos!

[GaryBudd]

Carbking's solution wold work  but where he attached tubing at the top of the carb mine is just a blank boss.I just don't have the nerve to try  drill and tap.

[thehandleman]

The 289s has boss

the  517s has the boss's at top the bottom some has threads some don't but bottom cannot really damage anything just the top is tricky

the 517s is actuatly a coe truck chevy like 49-50 works very well once all rigged and looks just like the old 4a3's etc., 

good luck you can always take it off and take to a machine shop and ask them to drill and tap

[GaryBudd]

While removing the carb this morning I found anther spot where I might be able to apply Carbkings tubing solution.I have marked it with an arrow.Could this be used? I have to thank all that are working with me on this,I am a first timer with an antique car and I'm doing this alone.

[thehandleman]

Not sure what that does but sounds ok research it, and if you route the line make sure your linkage does not hit the new line, 

good luck

[maok]

Yep, that's where carbking  recommends. Its a vacuum port that you can use to tune the carb as well. Same place as mine.

Edited September 19, 2017 by maok
errors (see edit history)

[thehandleman]

Good luck!

[GaryBudd]

I got the tubing run and it did indeed solve the problem.While I had it running I thought with it up on jack stands I should see if the cluch is ok.Throw out bearing is hung up on bits of a sleeve. The transmission is marked T2C-1.Where would I go to find replacement parts?The photo shows broken sleeve.

[Taylormade]

If that sleeve is anything like the one I had in my 29 Plymouth, we got trouble right here in River City.  The piece fits on the front of the transmission over the input shaft and the throwout bearing slides on it.  Unfortunately, they are made out of some sort of pot metal that disintegrates over the years.  this is what it looks like on my 32 Dodge Brothers transmission...

 

 

Luckily, Chrysler figured out the pot metal sleeve didn't hold up and mine is machined cast iron.

[thehandleman]

Gary,

i have my 517s solid cast iton bottom what a B! To size and tap that cast iton steel it drilled fine but took all my strength to tap it or should i say get it started that parts done whew, 

In answer to next delema I think I have a spare tranny but I think its on your clutch housing side I am guessing from photos how far are you from hershey?

[thehandleman]

Here is one of my BB1 517s Carter drilled and tapped to prevent dripping fuel from flooding a hot engine,the intake side right on the hot exhaust pipe hopefully preventing fire, Thanks for the suggestion!

[GaryBudd]

I'm about 6 hrs from Hershey.When is the best time to go there for old car parts?

[thehandleman]

We set up on tuesday and there are more and more people who are hunting stuff before I even get close to setup, I would say you come on wednesday, saturday we pick up and head home, but if you are looking for parts wednesday, just my opinion. The foriegners are coming earlier and earlier as they spend huge bucks to cross the pond and they figured most good stuff is gone by friday and sat.

[thehandleman]

No parts list ever came up but i am on my smart phone

email the list to my email

thehandleman@comcast.net

subject desoto

[richasco]

Gary,

Sorry to see that your bearing retainer failed. Check your thread about the clutch for some replacement options. As stated by others, Hershey is a great way to find what you need. Also try posting a want ad in the for sale forum. You'd be surprised what people have on their shelves. I may be able to take some pictures of my broken bearing retainer so you can see what it looks like out of the car.

[seando]

On 9/17/2017 at 5:57 PM, thehandleman said:

GOOD LUCK!!!!!! SEND ME A PICTURE OF YOUR CAR NEED ANY PARTS???

I have a 29 DeSoto Model K. What parts do you have left? 

[thehandleman]

I DONT OWN A 29 DESOTO, I HAD A TRANNY THAT CROSSES TO IT AND TOOK IT TO HERSHEY, IF YOU READ ALL THE MESSAGES GARY IS THE ONE WITH A 29 DESOTO.

GOOD DAY

[Bill Harmatuk]

Thank you for the pictures.

I am also running a BB-1. The drip I'm told is the nature of the beast with the up-draft BB. I only have the drip when cold starting using only one small pump of the throttle and some choke.

Yes, the exhaust is directly under the leak / drip.

My family and friends get uncomfortable when they smell gas and see the gas vaporize on the hot exhaust.

I was also wondering what to do about the leak when my engine dust pans are painted and installed.

I've seen the pictures before and now it is a priority. Amazingly, I was talking about the re-circulation tube just 2 days ago.

 

Thank You, Again. (Might do this job today).

 

Bill H

 

[richasco]

Here is how my car is set up.  The drip tube passes through the pan and is offset from the exhaust. Please excuse the grime, it will be shined up once spring gets here.

[elkhorne]

Anyone know what the size and thread needed for the brass fitting to connect the drain port on the lower casting of the BB1 below the choke inlet and the same size and thread needed for the vacuum port near the top of the upper casting. My NOS BB1 has the hole drilled in the bottom casting but is not tapped. I’m going to have to get a plug tap of the correct size to tap that bottom hole. Hope someone can answer my questions so we can stop losing fuel.