1957 carburetor secondary vacuum pull off

[SlimerSnail]

How long is the shaft supposed to be? I had to tear into the carburetor due to sediment getting in it and noticed that the shaft seems too short. It holds the secondary butterfly open a bit which i dont think is right. There are different shaft lengths available.

Holley 4150 and 4160, 4-barrel Carburetor Primary and Secondary Diaphragms

www.carburetor-parts.com

Carburetor is original holley 4150 list 1273-1 "ford code ecz-ad"

Can't seem to find this information anywhere. 😕

 

[sre]

I had trouble with my carb. The spring that applies downward pressure to the diaphragm did not have enough strength to push it closed. I changed the spring to a stronger one and fixed the problem.

 

[SlimerSnail]

I had trouble with my carb. The spring that applies downward pressure to the diaphragm did not have enough strength to push it closed. I changed the spring to a stronger one and fixed the problem.

My issue is that even if I manually actuate the shaft the butterfly on the secondary is still held slightly open. I think the diaphragm's actuation shaft is too short. Someone must have swapped it out in the last 65 years. When I measured, it appears to be the 2.040" one but I suspect it's supposed to be longer. It occurred to me that I can partially re-assemble the carburetor, disconnect the linkage, and using calipers, estimate how much longer it needs to be. I'll post back tonight or tomorrow with my findings.

 

[Gforni]

I had trouble with my carb. The spring that applies downward pressure to the diaphragm did not have enough strength to push it closed. I changed the spring to a stronger one and fixed the problem.

Did you have hesitation at acceleration?

 

[SlimerSnail]

I played around with it some more and I think the correct length is the 2.040" one after all! I must have assembled it wrong earlier.