Model 94 carb leak

B

buzz882

Junior Member
I have a model 94 carb that was spewing gas out of hole in upper right side. Anyone seen that before, it was in a car I got that had not ran in a while.
 

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That's the air vent above the float bowl. One of 3 possibles: Most likely, a stuck non-metallic inlet valve, or a sunken float. Also possible, but less likely, your fuel pump is delivering more pressure than the carb can handle. Pumps don't get stronger over time, so unless you've done something there, forget this possibility.

Take off the top air horn, that's where both the inlet valve and the float are located. If the inlet valve is all metal, you're good, but check it for debris and varnish. The float may have fuel inside, causing it to sink, or it may have stuck down with fuel varnish. If you have varnish, it's a good time to remove and clean the carb anyway.
 
Fastest cleaning of the needle seat is one of them ear cleaning cotton tips in the cordless drill dipped in paint thinner...
Then put the steel needle back in tap it gently with a small hammer while rotating a few times..and it should be good to go.
 
buzz882 said:
I have a model 94 carb that was spewing gas out of hole in upper right side. Anyone seen that before, it was in a car I got that had not ran in a while.
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That hole is a feed port (not a vent) for a South Wind (or similar) gas heater. It needs to be plugged, or replace with another un-modified carb top.
 
"That hole is a feed port (not a vent) for a South Wind (or similar) gas heater. It needs to be plugged, or replace with another un-modified carb top."






I don't think so. pretty positive that's a vent hole that was used on the later 94 type carbs. The hole is over the accel pump inside the carb, and nowhere for a heater to pick up or put in fuel without making the gasket seep a lot.






Sal
 
Sal, I've got several 94s, 2100s and 2110s and all vent internally. The pictured carb hole is too large for a vent, and looks like I've seen on carbs modified for a gas heater, mainly on Strombergs.
 
V8 Bob said:
Sal, I've got several 94s, 2100s and 2110s and all vent internally. The pictured carb hole is too large for a vent, and looks like I've seen on carbs modified for a gas heater, mainly on Strombergs.
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Bob, Sal is correct. This was the second of three different locations for the vent on 94's, the first being an oblong vent high on the driver side, which was plugged for the other two locations. Second, the location seen in the picture angles in over the accelerator pump and through to the bowl. Your later 94's have the vent as an angled tube inside the air horn.
 
Sal and Alan, I've had '46-'48 94s and all had the internal vent, so maybe this was an earlier vent? The hole just looks too large for a vent, compared to the much smaller Stromberg 97/84 and later Holley external vents, but...I could be wrong. :o:)
 
Bob, the actual vent is indeed smaller than that external hole. The vent itself is beyond the accelerator pump, that hole only providing tooling access to the vent point. And yes, it was earlier.
 
Sure seems like a great place for crud to get in and collect, since it doesn't appear that the air cleaner would cover it.

Mike
 
Black Fifty said:
Sure seems like a great place for crud to get in and collect, since it doesn't appear that the air cleaner would cover it.

Mike
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Yeah, they did stuff like that back in the day, before emissions standards were involved. There are other model carbs that are even more likely to get dirt in through a vent.
At least on the Holley 94, the hole is vertical, and facing the rear of the car, so no air/dirt coming from the fan.


Sal
 
ford38v8 said:
Bob, the actual vent is indeed smaller than that external hole. The vent itself is beyond the accelerator pump, that hole only providing tooling access to the vent point. And yes, it was earlier.
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The op started a similar thread over on the HAMB that I also posted on, but Bruce Lancaster provided info agreeing with you that the hole is an early vent method. Below is part of my response on the HAMB.

"I admit I was wrong about the hole. ....My earliest 94s are post war 59 and is why I don't remember seeing this before....well, that is until I went through a box of misc carb parts,.... and found a 94 top....with that same hole!
clear.png
Learned something today!"
clear.png
 
V8 Bob said:
The op started a similar thread over on the HAMB that I also posted on, but Bruce Lancaster provided info agreeing with you that the hole is an early vent method. Below is part of my response on the HAMB.

"I admit I was wrong about the hole. ....My earliest 94s are post war 59 and is why I don't remember seeing this before....well, that is until I went through a box of misc carb parts,.... and found a 94 top....with that same hole!
clear.png
Learned something today!"
clear.png
Click to expand...

Bob, this is good. It's exactly the kind of conversation that makes the FordBarn such a valuable resource. Would that we could all be educated as easily and have fun doing it! ;)
 
More often than not, a leaking carb is due to the over tightening of the screws that hold it together. When a leak is noted, often the screws are turned down to try to fix it. This results in warping of the pot metal body and top. Place a piece of fine emery cloth on a piece of glass and gently rub the gasket surface on it. Any voids or damage will be plain to see. If not severe, a new gasket set will likely be the fix.
 
I’ve seen a lot of holes in the tops of carbs, most drilled by some backyard mechanics to vent a carburetor. Some, maybe, were factory , but most are not.
 
"More often than not, a leaking carb is due to the over tightening of the screws that hold it together."




Not when the gas is spewing out of a hole 1 inch above the gasket.


Sal
 
Here is a link that has excellent information an the 94s. I have the same hole drilled in my spare 94 that came with the purchase of my ford. Mine does not appear to be done by the factory. It is also done in a place where you could not screw in a fitting. I believe the previous owner did this to increase venting.
Here is a link.

https://www.scribd.com/doc/249258710/1949-1950-1951-Ford-Passenger-Car-Shop-Manual
 

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As stated above, this was done when the carbs were manufactured. Either that or the same guy that wanted to increase venting did it the same size, in the exact same spot on thousands of carburetors.


The shop manual you posted didn't show the venting in the carb section.


Sal
 
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