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Carter B&B Carb leak


jimy

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I got my truck (1935 Dodge KC) out of the garage for the first time this year last night.  Started right up but it was running poorly/stalling so I pulled it up next to the garage.  Heard a hissing sound, opened the hood and I saw gas dripping from the lower part of the carb.   I ended up pulling the top off the carb and looked things over.  A small amount of crud at the bottom.  Cleaned most of that out and also cleaned the float valve.  Put it back together and got it safe back in the garage.

 

Today I ran it for a few minutes at idle, no leak noticed.  Then held a higher rpm, no leak noticed.  Then revved it up and down a bunch of times to get the accelerator pump going.  At that point I did notice a little gas seeping around the top gasket.  Big enough to be a problem, but small enough that I could have missed it earlier in my checks.  Top gasket seems kinda stiff and dry.

 

I don't want this happening again - if I had taken it out on the road there could have been a fire.   The float level is supposed to be 5/64ths from the top.  It is currently closer to 1/4" - way low.  I assume this is measured while holding the float in place to close the needle and then measure (or just hold the carb upside down).  If true, that is way off.  But I'm not seeing how less gas in the bowl would cause a leak.  I have a feeling the float valve is incorrect because it has a groove near the end - I have seen this on other carbs so it can slot into a groove on the float.

 

 I'm considering getting a kit, mostly for the new top gasket and new float valve and seat.  The accelerator pump plunger on this is brass and not included in kits (perhaps not even available).  It does shoot a nice stream of gas into the venturi.   And of course I will adjust for the correct float height.

 

I like this plan, but I don't want another leak.  Is it possible there is another reason for the leak besides a bad float valve?  Float does not have a hole but I can't be sure it is original and correct.  An incorrect shape could change the measurement.   I should have measured the fuel level when I took the cover off last night - it was maybe 1/4",  maybe twice that or so...

 

Carb model is CTD2 which is correct for a 35 KC.

 

thanks,

 

Jim

Edited by jimy
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I did a sarch on ebay use this topic label:  1935 DODGE TRUCK, CARTER CARBURETOR SPEC, INFO SHEET

The carb CTD2 is listed under this spec sheet it might also have the carter rebuild kit that is the correct kit for your carb.

Also the horn which is the top part might not sit completely flat on the top of the carb. Could take a piece of flat glass but some sand paper  down and then lightly move the air horn to remove any high sport and then reassemble the carb.

 

Hope this helps 

Rich HArtung

desoto1939@aol.com

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Thanks for that - I did see the info sheet on Ebay - not sure I want to buy without seeing the whole page - but if I saw it I wouldn't need to buy it.

 

I got the float specs from Mike's Carburetors web pages.  Also just found a nice article that has a good picture confirming the method to adjust float height.

 

https://www.allpar.com/fix/fuel/carter-BB.html

 

I will check the flatness of the horn...

 

Jim

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   On the newer model BB, there is a U shaped retainer that goes upside down in the float pin slots. When the top is put on the carb, it holds the retainer pressure on the float pin. So it can't rise up when the bowl fills. It's #12 on the parts list in my kit. 

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Yes, my carb has that as well.  Seems to be ok, but I will be extra careful to make sure the top holds it down snugly.  Wish it was a bit more like spring steel, but it is likely fine.  Almost no metal parts in the rebuild kit beyond the float valve and seat.  Far cry from most 70's motorcycle carb kits which usually include all new jets...Jim

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