Where is my mixture adjustment screw?

Keep it on topic, it will make it easier to find what you need.
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bradartigue
Posts: 2183
Joined: Thu Sep 20, 2007 2:35 pm
Your car is a: 1970 Sport Spider
Location: Atlanta, GA

Re: Where is my mixture adjustment screw?

Post by bradartigue »

Well crap, I wrote a nice long post and Safari crashed.... here it goes again.

That port is for a stock air cleaner. It is described in the ADF guide on my website, basically a method to draw crankcase gas at low speeds (idle). I would not bother with it.

That isn't a stock carburetor. 32ADFAs on FIATs had mixture adjustment screws where you have a plug. So either someone plugged yours with a very stock looking part, or the mixture screw isn't in that position (is it on the other side, is the primary barrel on the other side?) I don't see a the identifying marks on that carburetor, are they anywhere on that carb? Weird to see a Weber on a FIAT, if stock, without the stamp.
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stuartrubin
Posts: 273
Joined: Sun May 24, 2015 11:10 pm
Your car is a: 1975 Fiat 124 Spider
Location: 44122

Re: Where is my mixture adjustment screw?

Post by stuartrubin »

To add to the story, I went through the pile of receipts from the previous owner and previous-previous (!) owner and there is a receipt for a "Weber 34 ADF Performance Carb."

Does this offer any clues?

Thanks for your writing your response - TWICE - considering your browser crashing!
Stuart
1975 FIAT 124 Spider
Il Mostro di Frankenstein
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bradartigue
Posts: 2183
Joined: Thu Sep 20, 2007 2:35 pm
Your car is a: 1970 Sport Spider
Location: Atlanta, GA

Re: Where is my mixture adjustment screw?

Post by bradartigue »

stuartrubin wrote:To add to the story, I went through the pile of receipts from the previous owner and previous-previous (!) owner and there is a receipt for a "Weber 34 ADF Performance Carb."

Does this offer any clues?

Thanks for your writing your response - TWICE - considering your browser crashing!
It may very well be - but the capped mixture screw is a first for me. There isn't a mix screw on the other side, is there?
80spiddy
Posts: 180
Joined: Thu Mar 05, 2015 8:06 pm
Your car is a: 1980 spider 2000

Re: Where is my mixture adjustment screw?

Post by 80spiddy »

My 80 has the mixture screw on the other side. Maybe you have this era of carb.
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stuartrubin
Posts: 273
Joined: Sun May 24, 2015 11:10 pm
Your car is a: 1975 Fiat 124 Spider
Location: 44122

Re: Where is my mixture adjustment screw?

Post by stuartrubin »

80spiddy, thanks for the tip. I can't confirm it now since it's in the shop (unrelated fixes to oil leaks in the engine seals).

Would it be too much to ask for you to post some photos of your carburetor, especially where the mixture screw is? I'd like to compare it what I have.

Thanks

Stuart
Stuart
1975 FIAT 124 Spider
Il Mostro di Frankenstein
User avatar
bradartigue
Posts: 2183
Joined: Thu Sep 20, 2007 2:35 pm
Your car is a: 1970 Sport Spider
Location: Atlanta, GA

Re: Where is my mixture adjustment screw?

Post by bradartigue »

80spiddy wrote:My 80 has the mixture screw on the other side. Maybe you have this era of carb.
No you either have the carb mounted backwards or have a non-stock carb. "The other side" on the Webers FIAT used is the secondary, you wouldn't idle off the secondary throttle plate.
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