Carter B&B carb gaskets - always wet as designed?

[rrunnertexas]

My 1935 Plymouth PJ has the Carter B&B carburetor and was running pretty well, just a hit of a miss here and there at idle.  It was obvious that the carburetor had been leaking fuel for some time as shown on the manifold and carburetor.  So, I pulled it off and rebuilt it with new gaskets and a needle/seat, hoping to cure the slight miss and the fuel mess.

 

After installing it and running the car for about a minute, I see the top gasket is wet with fuel.  OK, so maybe I set the float incorrectly at 5/64ths.  Resetting it for less fuel in the bowl did not change the top gasket wetness.  The motor runs but not as well before the rebuild. 

 

Were these carbs designed to have wet gaskets and leaking fuel?

[rrunnertexas]

Also an image of the wet, top gasket.

[allbizz49]

Put a straight edge across both surfaces. Top or base or both might be a little warped. 

[chrysler1941]

2 hours ago, rrunnertexas said:

Were these carbs designed to have wet gaskets and leaking fuel?

Nope

[greg g]

Take the top off put a piece of 400 sandpaper on a piece of glass pane ot other known flat surface and give enough swipes to remove any high spots. Clean it good so you don't transfer any grit to the carb and reassemble. When you put the top back on, use a star pattern to snug every other screw.  Don't over tihjten.

[Andydodge]

Apart from checking the surfaces with a straight edge place the top on the bowl without a gasket and check whether there is any gap between the two mating surfaces........there shouldn't be any gap between the two..........try running a flat file against the surfaces but you may have to try & find another carby..............andyd,      

[Sam Buchanan]

Put the old needle and seat back in the carb and see if that makes it happier.

[rrunnertexas]

Putting a straight edge on the top cover reveals warping.  In the picture I have an LED flashlight on the other side, revealing the gaps between the top and base.

 

I did some filing with flat file, but the warping seems a bit much for that method to correct.

 

I'll put it back together with the gasket and see what happens later today.

[T120]

12 hours ago, greg g said:

Take the top off put a piece of 400 sandpaper on a piece of glass pane ot other known flat surface and give enough swipes to remove any high spots. Clean it good so you don't transfer any grit to the carb and reassemble. When you put the top back on, use a star pattern to snug every other screw.  Don't over tihjten.

Using Greg's suggestion,I would also add - use a figure 8 pattern when truing the surface...

[Booger]

what if you were to double up gasket?

[DJ194950]

My 50 with later B&B had that issue. Wet been leaking for some time.

 

No glass lying around, then it hit me the car has nice heavy flat glass side windows!

 

Taped a whole sheet of wet/dry sandpaper  (320-400g) to the glass,(smooth side down!!) wet it and sanded the upper lid of carb until the sealing surface was all shiny. Took a bit. Sure shows the warping quite fast.  Keep paper wet throughout the process.

 

No more leaks. As mentioned new gasket and tighten as little as necessary.

 

DJ

Edited May 5, 2021 by DJ194950
SP

[rrunnertexas]

Well then, it may be possible to keep using the flat file or sandpaper to rid the high spots.  Just seems like pretty large gaps.

 

A double gasket, maybe.

 

I don't suppose there is some sort of gas resistant sealant that could be used in the areas that show the large gaps?  

[Jerry Roberts]

I have used Seal-All on gas tank sending units . it is made for gasoline sealing and is probably found in most auto parts stores . 

[kencombs]

If you have a shop  press  that would be my choice to remove the bend.  After all it was bent to begin with using the screws, so a tool can remove the bend.  Put as shim of some sort under the places that touch the body and slowly push it level.  It will take more than one attempt as it will spring back a little when the pressure is removed.  I've even used a little heat from a propane torch to help it along.       A little lapping later would be OK, but it's better to rebend than cut some off, IMHO.    A good bench vise works too, just not as precise.

[DJ194950]

Reshaping pot metal is very tricky. Breaks quite easily at low pressures.  The pro refinishing shops use someone with a special touch and propane torch and Experience, much! to replace some almost impossible to replace parts for repair .

 

Not my choice as above - but??

[TodFitch]

Over on the AACA forum I have read suggestions for flattening warped pot metal that, if I recall correctly, involve heating the part in boiling water to soften it a bit then weighting it down on a flat surface like a piece of glass. I don't know if it would work but it seems like it wouldn't be too damaging if it didn't.

[DJ194950]

Sounds much better than a press!

 

DJ

[allbizz49]

Looks easily repairable to me. Do as suggested earlier and sand it on flat glass or steel. I've done this with good results.  I usually start out a little coarser, 220-240. Work your way to 400.  Good luck.

[rrunnertexas]

I found a nice thick piece of glass and put it on the bench.  Started with coarse paper and then moved to finer grit.  After about an hour of sanding and checking, the warping is now drastically reduced.

[rrunnertexas]

Assembled with a thin layer of this Permatex fuel resistant gasket sealant.

 

I only found one slightly damp area near the barrel, a huge improvement from the fuel pouring out the sides of the bowl.

 

Certainly do appreciate the ideas and experience shared here.  Together we saved this fine Carter B&B carburetor!

 

 

 

 

[DJ194950]

Assume you flattened the top lid also?  It is usually the worst piece.

 

Should work now!

 

DJ

[rrunnertexas]

DJ - yes the lid is where all the warping was and where the sanding was done.  The bottom was close to flat.