
Here are the 4 bodies and the T4XA. The T4XA has a smaller throat but all the parts on it fit the T4X

Here is the T4XA. The body of the T4XA is too small a diameter but many parts fit. This is a good illustration of the idle jet air adjustment . The idle jet is vertical and the air adjust id the knurled horizontal needle

Reaming the jets . here are a few main jets. The drill bit is so small I needed a small Jacobs chuck to hold it

I used an old cut up carb body to hold the needles. I started by boring with a .037 drill bit and then hand reaming with a .038 ream which is what Henderson calls a #20 jet. The ream is very hard to find and was a gift from Chris Chemberlain

This is Vic. He has been helping for most of the Summer. I could not have gotten this far without his help

After the bodies were honed the venturies were too small. I put them on the lathe and cut a groove and fit an O ring on the outside and they then fit nice and tight in the carb body
OK, Been awhile since any posts. I have been working every day after work until late to get this finish and have had several problems. The good news is Tim Cantele met me at Rhinebeck with my 4 Zenith T4X carbs and a Zenith T4XA that he found at a swap meet. Tim took all of my Crab bodies and machined them for me. 1st he machined all mating surfaces flat. The he calculated the angle of the throttle disc, then he honed the bodies and made new throttle discs to fit in the honed bodies. He also refit the throttle shafts. What I got back were 4 bodies that had throttle discs made to fit their bodies. Tim did an amazing job for me.