Carb Issues

[M-37Bruce]

Enclosed is a video clip of my m-37, my engine is 10 years older than my truck, 1943 a french rebuild to boot. It has a Zenith Model # 29 B installed, it is also french.
I have done a through cleaning and a mild rebuild of said carb with a kit I bought from Sid Beck several years ago. Anybody got any ideas, I'm thinking a new or new to me carb?
TIA,

 

[WarrenD]

First thing that comes to mind is rotted rubber parts from ethanol fuel. I'd go with a rebuild kit from Then and Now Automotive.

 

[M-37Bruce]

All gaskets/rubber stuff is new, I think I'll contact Then & Now Automotive any way.
Thanks Warren!

 

[JGBallew]

Pushing on the linkage toward closed, causing a change in RPM is linkage out of adjustment, followed by a worn throttle body. if the body is worn, they can be bushed and the shaft replaced.

The stumbling on accecelleration can be a lot of issues, including plain bad gas.

 

[M-37Bruce]

Gas is fresh, tank as well? Every time you touch the throttle it goes to idle, great too? I'm thinking the linkage is OK, but the brass bushing that goes thru to the rod/governor is shot?
I am going to add a couple more pic's for y'all to check out.

 

[M-37Bruce]

Geting Worried

First one is original, French made, second one NOS, scavenged from a NOS Zenith # 29 B made in the USA Wont work!
Took me a while to figure out how to post.

 

[JGBallew]

Gas is fresh, tank as well? Every time you touch the throttle it goes to idle, great too? I'm thinking the linkage is OK, but the brass bushing that goes thru to the rod/governor is shot?
I am going to add a couple more pic's for y'all to check out.

You can confirm the air leak by spraying the area around the shaft with something like MMO or motor oil.

I'd remove the linkage and set up the base idle before doing this though, to eliminate any springback caused by the linkage.

Your part incompatability may stem from putting parts from one kind of Model 29 to another.
The one on your truck in the vid looks like it has a governor. IIRC that's a 29W.(or 29R?) Anyhow, you have two Zenith 29 carbs, but the parts won't interchange because they are different models of the same carb.
I know there were a bunch of model variations in the model 29.

If you have a known good and new one, you might bolt it up without attaching the linkage to see if it runs better.

 

[M-37Bruce]

I thought about that, but all of the linkage and fuel supply are on the opposite side of the original?
Thanks, I still might do it, just to check it out.

 

[JGBallew]

I thought about that, but all of the linkage and fuel supply are on the opposite side of the original?
Thanks, I still might do it, just to check it out.

Right, all you're doing is eliminating the "old" carb from what's causing the stumbling and crazy idle. If it runs better with the "new" carb, you've found the source of the trouble.

Rebuilt or not, if it's not working right you're not getting anywhere, and having the old carb overhauled or replaced is then the obvious fix.