Subject:TX4 and TX3 1/2 Zenith Carbs Date:Sat Apr 11 22:14:22 2009
Response to:1491
I found old post and am looking for a picture of an actual Henderson motorcycle 23-24-25-26-27-28 carburetor. I would like to acquire a few more TX4 types TX4F carburetor TX3 1/2. I have TX and TX4 but seem to not have enough.

Perry, I'm giving up on this. Your pictures are reversed. I'll lay all 14 of my T4X bodies on the table plus the two 3&1/2Xs and they all have the front adjustment. If that right side body is an X, it could easily be a car application. Further, all that Google info is car related. Henderson motorcyles were only a small application of the Zenith sales and the Schwinn engineers dealt with what was available to them off the shelf as their production numbers didn't warrant a special carb. In the best interests of learning there should always be lively debate. I can only go by what I've seen and I've seen some pretty good K's and '22s with X carbs. In summary, if someone brought out a a K or an early Deluxe on a judging field with an X carb, I wouldn't dock it a hair of a point for that item. I want to see an original Zenith production list, with applications before I revise my opinion.

Carb discussions are endless. 1936/37 Indian fours also used Zeniths, same as American Bantam cars. On a swop meet table they look identical but there is a small difference in the pitch of the choke area of the bodies.

I'm going to take the rare step of disagreeing with Steve (every hoppergrass must eventually leave the master (that's an oblique reference to a 1970's TV show for those of you not from North America)). I think the 1923 parts book is correct when it says just T4 and not T4X. T4X's were used on lots of different cars. Chevy's for sure. Do a google search on Zenith T4X and one of the first handful of hits is someone on a Chevy forum asking about T4X's and another opining that T4X's first showed up in late 22. If the same is true for Henderson then 1922 and some 1923 DeLuxes were fitted with the T4. Maybe the T4X never came into use on Hendersons until the 1924 model year? I have a photocopy of a page from a 1926 Zenith manual that shows the T4, T4X and ST4 as fitting the 22 and 23 DeLuxe. Given it's 1926 date and I think we need to give more weight to what the 1923 Henderson parts book lists. Zenith may no longer have made T4's by 1926 and simply were listing T4X as a suitable replacement.
I'll attach a photo comparing a T4 body (on the left) and a T4X body (on the right). You can see they're quite different in the area where the idle tube/jet connects. The T4 having the adjustment in the tube and the T4X having it on the body. By the way, this T4X is a car carb since the adjustment is on the back side of the carb rather than the front ... Perry

Started a new thread so we wouldn't have to read through everything. Steve you are quite correct. All the parts books through 1926 (I've never seen 27/28 with the valance fenders and dash parts list) specify only 3&1/2 or 4 WITHOUT the X. I suspect the X may have come from Zenith as a designation for a Henderson m/c application as opposed for possibly a small car or marine application. If you note in the 18 to 23 inclusive parts book, some of the carb components have an X suffix which may have been their designation for the special m/c parts. Seems I have a T4 body and the main diffference is that the throttle shaft arm would be to the outside rather than the inside if it were mounted on the bike. I just found an instruction for the "Operation and Care of Zenith Carburetor Model T4" Among applications include are Ford Model T trucks, Chevrolet Model 490 cars and Sampson trucks. It also states when contacting Zenith for info, specify make model and serial number of your car. This also has a parts illustration that shows things we do not use on our bikes.

When disassembling your carb, you've probably noticed the jets have numbers stamped on them. They correspond to orifice sizes. These relate to carbs set up for sea level, high altitude, high heat ares, cold weather areas etc as I've seen the designations for other carbs for other vehicles. Also they reflect changes and improvements over the years. If any of you have fooled with Flathead Fords of the 30's you'll clearly understand the issue here.

I look all the time but have been unfortunate in coming up with decent Zenith info. Best I now for what little I have. In MHO I'd recommend we accept the X designator as correct for our bikes, simply because of the shear numbers seen. sooner or later an application list will show up.

Hey, Steve what do you mean no illustrations in the 18-23 parts book? How about that snazzy winter cover for the right side of the motor. I could use one of the right now.