Zenith Carburetor Rebuild Kit Needle

[bplust]

Hi all,

I am rebuilding the carbs on my 1968 280S.

In the Walker kits I bought, I noticed that the needle, while the same overall length, as well as the length of threads & length of taper, are the same as the needles that came out of my carbs, the taper of the needles that came with the kits starts much wider. The needles that came out of the carbs are of course worn, but the difference is significant (in my opinion).

Has anyone else experienced this and have any thoughts?

Thanks in advance for any replies,

Bryan

[JeffreyNMemphis]

Hi Bryan,

Trust your instinct. If it doesn't look right, it probably isn't.

It would be a good idea to photograph the two side by side and email to Walkers. They may have made a mistake? Or maybe able to send the correct one to help you get going?

Post a copy here... We love pictures.

Happy Friday!

Jeffrey

[bplust]

Hello Jeffrey,

Thank you for the reply, and a Happy Friday to you as well!

How do I post pictures from my hard drive onto this site?

Thank you,

Bryan

[bplust]

Nevermind, figured it out (I think).

Arite, so the first picture is the new and old needles.

The 2nd and 3rd pics pertain to a question I have about the accelerator pump. On the other carb, the pump has an e-clip at the top of it. This one does not. Does anyone know how to pull this pump to replace the seal? I don't know if it's visible or not, but in the 3rd pic, I am showing the other side of the pump, which has a recess in it akin to if you shaved a Philips head flat.

4th pic is the car in question (not bad for a Vermont car). Pretty darn solid for its age, needs rockers; doors (including the bottoms) are solid, making me think that it sat a lot and grass grew through it.

5th pic: I am new to these carbs, and know that carb kits cover many variations of a carburetor a lot of the time, but I have that always-fun question: Where do these parts go?

Thanks again,

Bryan

[bplust]

Arite, so I got the pumps out (but not without issue).

The pumps are of a different makeup between the two carbs. The one of the left (the one I showed in the previous pictures) has a plastic bottom and a rubber seal (akin to the one that came in the Walker kit), and the one on the right has a metal bottom, with a paper seal (not shown because I cut the majority of it away).

Regarding the "but not without issue", I put a small hole in the pump to the left (with the plastic bottom) when gently tapping it out with a Phillips head I modified to fit the pump.

A few questions:

1. Did these cars come with different pumps between the two carbs or is one a replacement pump?

2. If one is a replacement pump, is it the one with the rubber seal?

3. Can the metal pump with the paper seal accept the rubber seal that came with the kit?

4. While I'm sure some JB weld or delicate plastic welding would hold up, does anyone know of a source of these pumps?

Thanks in advance for any replies,

Bryan

[bplust]

Arite, so I have the plastic-body pump patched up and pumping fuel nicely with the new seal installed.

Upon further inspection, I noticed that the metal-body pump has a larger diameter seal surface, and cannot accept the seal that comes with the rebuild kit. I could lathe it down to a proper diameter, or, does anyone have one of these pumps laying around? Or have a source for them?

Also, what I originally thought was some kind of paper/fiber seal on the metal-body pump appears to be leather... cool!

Thanks in advance for any replies,

Bryan

[gmog220d]

Leather cups can often be re-used if they're not tore up, at least until you can source a proper replacement.

I'm not familiar with the carbs that came on these cars - always had diesels. But I've worked on carbs on other cars (Chevy, VW, and others). Looks to me like you've got two different carbs there, given the differences between the two accel. pump assemblies. Might help to ID the odd one and look for a kit that has what you need for it. Are the castings and numbers the same between these two? Pics?

A local carb shop might be of help, if you've got one around you. They often times have parts laying around from other carbs/kits that will fit and work for your application.

[bplust]

I believe the carbs are the same, but I will check. I figured that the accelerator pump with the leather seal and the metal body was original, and the one with the rubberized seal and the plastic body was a replacement pump.

Unfortunately, the leather seal was junk :-(.

I swapped the plastic pump into the other carb (the one that came with the metal pump), and it is producing a steady stream of fuel.

I will get some pics later. At the moment however, the carbs are disassembled in my shop. But carefully inspecting them, everything seems the same.

Bryan

[gmog220d]

I see. Those pumps sure are different! Short of someone around here coming to your aide I'd be looking for a carb shop. Maybe you could acquire another carb for parts. Never hurts to have an extra on the shelf.

Something else that I've dealt with on carbs is worn out throttle shaft bushings that make it difficult/impossible to tune them at idle. The air leaking in around the shaft leans them out to the point you cannot adjust them anymore. You never said why you wanted to rebuild yours. If difficulty tuning them at idle had anything to do with your decision you might look at how the throttle shafts fit in their bushings. Good carb shops can re-bush them for pretty reasonable money, especially if you take them a stripped carb they don't have to take apart.

[bplust]

Howdy,

Thank you for the reply.

While I have never bushed shafts on an automotive carburetor, I've done a few dozen on obsolete chainsaw carbs with excessive throttle shaft play. I feel that the throttle & choke shafts are tight in these carbs, although that is just intuition.

I wanted to rebuild the carbs because, after I freed up the fuel pump, the car would only run while tapping the float bowls. Once inside the carbs, I found that one had a sticking inlet needle, and both had torn secondary diaphragms & bad accelerator pump seals.

If anyone has an accelerator pump laying around, please contact me. Otherwise, I'll probably end up machining this one down to being able to accept (what I'm assuming is) the newer-style seal. It is fortunate that the "older" seal is larger ID than the "newer" one!!!

Thanks again,

Bryan

[bplust]

Oh, and just for context, regarding the picture that shows the two pumps, they are the same length when assembled. The one that is longer in the picture is as such because I removed an e clip that compresses it down to the same size as the shorter pump in the picture. This definitely should have been mentioned earlier.

Here is a picture to clarify; the pump on the right in this photo is the one that was spread out in the previous photo:

[gmog220d]

Right on. The pump details might have been apparent to someone who is more familiar with these carbs, unlike myself. But it was good of you to clarify.

Keep up posted on your carb project, how you get it all together, etc. Carb work is something I like hearing about, after all the work on them I've done in the past, especially in the VW realm (Solex, Kadron, Weber).

Good luck!

[bplust]

I got the metal body accelerator pump to spray fuel very nicely today.

I initially tried just putting the new seal on where the old one was, but the OD of the pump was too large for the ID of the seal.

The bottom of the pump comes apart where the leather seal was (see the read arrow in the photo). I separated the pump just enough so that the new seal ID could fit, and then tapped the pump back together (not too much, as you don't want to crush the ID of the seal and deform it). Separating the pump bottom like this also allows you to clean out any remainder of the old leather seal.

It sprays fuel very well now.

Bryan

[Ziad]

I have the two pumps listed in the parts for sale section