Bendix carbs

[Omarttentmaker]

I've been on another site recently trying to solve the problem of a leaking Bendix carb. I cannot figure out why the rubber tipped needle will not shut the gas off. Carb is set up correctly as to float height. But when I install the float and attempt to test the needle and seat by suction through the gas inlet nipple, it won't hold suction. Wondering if anyone out there might have an original all steel needle for this brand of carb. I've been led to believe they exist, and I'm thinking if I can get my hands on one I can at least attemp to lap the tapered face on the needle to the seat. Anyone got any other ways to overcome this dilemma?

[T. Cotten]

Bendixes, Omar,..

(Or is it Bendices?)

Are way out of my zodiac, but the "Zenith" kits on my wall have *rubber* tips.

There may well be a nearly identical steel or Monel needle for automotive applications, Good Luck!

....Cotten
PS: You may want to take a pencil or something and make sure a suck test will work.

[Omarttentmaker]

I know the suction test works as I have covered the whole top of the brass piece with my finger, and it holds drawn air. I have read that the whole brass piece can be replaced, but I find that hard to believe as the piece is basically pressed in blind. One would have to come up with some pretty exotic removal tools. Having said that, it just dawned on me that if another seat piece were available, I guess a 3/8-24 tap fashioned as a slide hammer would work. But that precludes the fact that a replacement piece is available. I even suppose I could manufacture one if it came down to that. I could make a lap arbor also, but I can't measure the included angle on the tip very accurately. Thanks for your input.....cheers....Omar

[T. Cotten]

Sorry I don't know what the brass thingy is, Omar,..

But nobody else replied.

If the rubber needle replacement is available separately, better stock up!

(My experience with modern carbs is if you can't throw parts at them, throw them in the bin.)

....Cotten

[Omarttentmaker]

Sorry I don't know what the brass thingy is, Omar,..

But nobody else replied.

If the rubber needle replacement is available separately, better stock up!

(My experience with modern carbs is if you can't throw parts at them, throw them in the bin.)

....Cotten

the brass thingy I'm referring to is the piece that's pressed into the floor of the carb that captures the needle body. It extends about halfway into the crosshole where the inlet fitting screws in.

[dukekleman]

Omar,
There are a few areas of failure when it comes down to vacuum testing those carburetors at the fuel inlet.

It sounds like you have concluded that it is indeed the needle and seat union as the failure.
I have used the Viton tipped needle with success and recommend you use it.

The Brass seats are interference fit into the carburetor body and would require removal on the lines of what you described.
I'm not sure who sells a replacement brass seat because I have never looked for one, however there used to be new Zenith carburetors available all over from sources like Drag Specialties.

[vph-d]

I've found the rebuild kits made by Facet to be much better than the other kit, especially the accelerator pump.
vph-d

[Omarttentmaker]

Many thanks to all that replied. Wanted to put an end to the story. I disassembled all the carb bodies I had, and installed every needle I got. After 7 tries, I found one that actually worked! Set the float a tad low (a little more than 3/16" gap between the carb floor and the float). Used a main jet/discharge tube that was stamped C66-184. My reasoning for this was I believe it's better to start out rich and dial the adjustment down. I'm using the screw with the spring underneath at the top of the carb. The only thing bothering me is the piece that extends into the jet is not quite concentric with the big hole in the top of the jet, but I don't see that it matters, as when setting the carb up, the instructions say to screw that adjustment down until the spring binds. So the point on the adjustment shaft never really touches anything in the jet. If I find down the road that there's a flat spot at idle, or mid-range, I'll put a different jet in and the non-adjustable screw assembly in. I have 5 or 6 jet/discharge tubes, C66-156, 157 and 158. So a happy ending, but it ain't over yet.

[otis71]

Problem solved with the float needle but if this arises again I’ve successfully lapped the seat with the tapered end of a #2 pencil. According to the parts book the seat isn’t replaceable.