Roadster Rich
Senior Member
Working on deciding which old carb to rebuild. I have two and both I have had for over 30 years, just sitting in a box of parts. This one has me puzzled, but then I am not very well versed on any but my two cars so many of you may have seen this before.
Here is the base of one of them.

I have never seen one with anything but the plug on the bottom. This one has this assembly in the plug hole.

Inside the hole it appears that the screw in jet is deeper than my others, and it has a washer in place for this screw in needle adjuster to seat tightly against.
Is this a common thing to have on a Zenith Carburetor? Do I just throw it away and rebuild with the standard I am used to?
Here is the base of one of them.

I have never seen one with anything but the plug on the bottom. This one has this assembly in the plug hole.

Inside the hole it appears that the screw in jet is deeper than my others, and it has a washer in place for this screw in needle adjuster to seat tightly against.
Is this a common thing to have on a Zenith Carburetor? Do I just throw it away and rebuild with the standard I am used to?