Carter B&B worn out? 1000 rpm minimum idle speed

[rrunnertexas]

I have worked on carburetors for 30 years and never ran across this before.  

 

My 1935 Plymouth with a Carter b&b always idles fast and I'm not able to get it below 1000rpm.  The idle speed screw is turned all the way out.  Knowing this, air must be entereing the engine from somewhere causing the high idle speed.

 

Removing the carburetor and putting on the bench with a flashlight below may have shed some light on the problem (pun intended).

 

With all this air entereing past the throttle blade in it's closed position, this can't help with the idle speed.

 

Anyone else run into this?  Typical for this type of carb and age?

 

Thanks for the help/advice, as always.

 

David

 

 

[rrunnertexas]

[James_Douglas]

First thing is take the linkage off the one end. Then carefully loosen the butterfly screws and see if you can get a tight seal. If you can then carefully tighten them. If not then you either need to buy a new shaft and butterfly or find a better core to rebuild.

 

James

[rrunnertexas]

James,

 

Thanks for the help!

 

I pulled the linkage and now see that there is light passing through the throttle shaft too.  That indicates a lot a wear and more air to be drawn in.  Instead of re-busing the shaft, maybe a tiny o-ring and some thick high temp grease will stop that leak.

 

Adjusting the butterfly made a slight reduction in the light passing through, but it still seems like a lot.  When it is closed, nothing should be passing, correct?

 

At this point in time, I'm thinking is it worth buying a few on ebay and try to piece one together or is it more efficent to buy a n228 replacement?

 

Thoughts?

 

David

[plymouthcranbrook]

Depending on your devotion to exact originality Langdons has a very nice system available  to install a progressive 2 barrel carb that works quite well  I have it on my 52 Cranbrook and really like it. Solved all my drivability issues.

 

http://www.langdonsstovebolt.com/

[James_Douglas]

Some 15 or more years ago, I got 2 or 3 carbs and rebuilt them. New throttle shafts and new butterfly's. Everything was done by the book. They still idled not so good. Not bad, but not great.

 

What I discovered is that there are emulsion tubes in the passages of the BB Carb. They are behind some of those little plugs that at hammered into the housing. The problem is that the old lead gas essentially sand blasted them over the years. They tend to go to crap.

 

The only way to fix it is to buy the tools and find the hard parts and rebuild the bare housing with new emulsion tubes.  About the time I was going to do that, I ran across a NOS Carter BB for a latter dodge that used a fluid coupling with a stick. It had an adjustable dashpot on it.

 

I put it on and it has been great for 15 years. Idles great and because it never saw any lead gas the tubes are not going to get beat to crap as the fuel flows through them.

 

Either you have to go all in and call John at the Carburetor Shop and pay for a couple of kits and then all the hard parts and tools...plus a day or two at the bench...or...get a langdon progressive as long as one is not running a fluid coupling.

 

James

[rrunnertexas]

The idea of trying to piece together a few carbs trying to make it work sounds like it could be frustrating.

 

I'm thinking a new carb is the way to go.

 

Several have recommended the progressive 2 bbl, which looks neat, but does require the 2bbl to 1bbl adapter.

 

The universal 1bbl from Mikes carburetors looks closer to the B&B in style and appears to be an almost bolt on.  

 

Anyone have negative or positive comments about that one?  I did read that it is made in South America, but the quality appears good according to a few comments.

 

Thanks

[rrunnertexas]

Update - For those interested in the Daytona 1bbl carburator (puchased from Mike's carburators) as a replacement for the original Carter B&B.

 

I installed the carburetor today and am impressed with the fit and finish.  All bolted on easily - the fuel line lined up, and the throttle linkage only took a minor adjustment to connect.  The engine fired up with less cranking on the starter and now it will easily idle at 600 rpm, nice and smooth.  I still have to follow the final adjustment instructions for the main jet, but it's first short drive as it is felt great.

 

See attached:

 

[rrunnertexas]

Linkage close up.

[Sniper]

Nice work, is there an adapter to fit the original style oil bath air filter?

[rrunnertexas]

There might be something available from Mike's.  The original oil bath air filter has been replaced on my car with a dry screen type (which does nothing).  It does fit perfectly on the carburetor.  I just need to find a small round air filter for it.