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Discussion Starter #1
My manual shows a weight on top of the ball for the venturi. My rebuild kit has a weight that's too large. Do I need this weight? I don't recall seeing one during disassembly.

My 2nd question is about the secondary check ball. I don't recall seeing one. It's very small. Do I need it? IMG_20201017_181400280.jpg IMG_20201017_182550135.jpg IMG_20201017_182636772.jpg
 

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Yes the weight is for the primary Venturi check ball. You do need it. Usually don’t see a correct new one in the kits. Always re used the old weight.

The secondary diaphragm check ball is usually missing from carbs I’ve taken apart. I was curious about it as well so I ordered a small bag of the correct size steel balls. To tell the truth I don’t see a noticeable difference with or without it. So I’d say it’s not needed.
 

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Discussion Starter #3
I didn't see a weight when I took it apart. The one in the manual looks like a cut off screw with threads. I can cut something to fit. Maybe an allen wrench unless there's a better idea?
 

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The primary side weight needs to be there. It has an effect on economy.
The ball is easy to deal with. I don't know if anyone sells the weight itself.
Primary jets are the smaller ones.
 

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Ball 0.187"
Weight is 0.094" dia x 0.889" long Weighs around 0.9g

The weight itself is approximate but pretty darn close.....
(the diameter may be closer to .125 - I'm not taking a carb apart to measure it)
Those numbers are close enough for government work.....
 

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Sorry. I've never seen the weight part available in the aftermarket.....
 

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Discussion Starter #11
Thanks GT289. Somehow I. Zoomed past your description of the weight. I can make that from a drill bit.
 

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There are a couple places that sell the weight. I’ll see if I can find the links.

Ok here you go, this is what you are looking for.

Autolite 4100 check weight-17-17

He also sells the check balls, but you don’t need the second one.
 

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He also sells the check balls, but you don’t need the second one.
Do you think Ford would have put something there that wasn't needed? That check ball controls the rate of secondary opening. If the secondaries open too fast you'll get a lean "bog" as there is no secondary accelerator pump or power valve.
 

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There are a couple places that sell the weight. I’ll see if I can find the links.

Ok here you go, this is what you are looking for.

Autolite 4100 check weight-17-17

He also sells the check balls, but you don’t need the second one.
That's interesting to know..... at over $6 I think I'd make my own to fit though.
The first reviewer of that product reminded me why it's tough to pin down the diameter of
the weight..... because there was apparently a design change in the primary
booster venturi screw's ID dimension at some point.
 

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My manual shows a weight on top of the ball for the venturi. My rebuild kit has a weight that's too large. Do I need this weight? I don't recall seeing one during disassembly.

My 2nd question is about the secondary check ball. I don't recall seeing one. It's very small. Do I need it? View attachment 769902 View attachment 769903 View attachment 769904
Yup, U need it. It's a ball check valve and it is used to seal or restrict fuel or air through an oriface.
And if there is a weight, that is used instead of a spring, to regulate the check ball valve's opening.
Go by the instructions, that's what they are for.
Otherwise, don't expect the carb to work right and you'll be doing the same job, again! 🤔
 
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