Advice

CnC79X19

True Classic
Going to rebuild these 2 40 DCNF-12 carbs and try to match the set for duals but have some questions. One is manufactured in Spain the other from my research is manufactured in Europe (the box states Spain as well and Marelli) although it isn't stamped in the casting with the exception of Weber in a place or two and the raised "W" on top and 40 DCNF 12 on the bowl. Could there be any issues since these are possibly not manufactured at the same time. The one without the place of manufacture is new while the other is considerably older. I'm searching for the throttle arm missing from one seen in the picture and my second question is how do I identify if these jets, emulsion tubes, air correctors etc are actually from DCNF's? Are they all created in such a way that they are specific to carb type or are some interchangable and cross with others? Also, carb kits?
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Weber decided to have fun with us all and mixed and matched jets. Some jets may be common on say IDFs and DCNFs and other jets may be common to DATRAs and DCNFs. It should be fairly obvious by looking at the jets in your DCNFs whether the jets/emulsion tubes, etc are the same type as those in the bags.
 
My guess would be that both were made in Spain. That's where a huge percentage of them came from for a long time after production in Italy declined.
As far as I've ever found, everything internally should fit interchangeably between them (both DCNF's) regardless of where or when they were made.
As Carl said the sizes of all internal components will be marked on them individually. That will allow you to compare between them - if that was your question.
Rebuild kits and other parts are readily available for the DCNF's ,so you'll have no problem finding whatever you need.
 
I should add, components that might fit more than one model of Weber are typically labeled for all models they fit. So when you go shopping for parts it will specify if it fits a DCNF or not. And there are charts that suggest the sizes of the commonly changed internal components for various applications. That may help give some idea of where to start with your particular use. Then any of the decent Weber tuning guides will assist in fine tuning from there. Unfortunately it usually requires several sizes of each part before finally dialing it in.
 
The carb on the left in the last photo that has Bologna Italy marked on top is the older one.
I hadn't noticed that marking. That may indicate this one was made in Italy, vs the other one from Spain. However it is my understanding they will still be identical. Later on there were some original Webers produced in other parts of the world that some people felt were of lesser quality, but I think they were still completely interchangeable.
 
My DCNFs were from Bologna circa 1980 but have different markings than the one in the photo. They also have the triangle marking as shown on the one from Spain. My guess is that the Bologna carb in the photo predates my Bologna DCNFs..
 
OK this is for the DCNF guys. Took both 40 carb lids off and this is what I have for an inventory per carb
#11 pump cams- good they match
30 and 32 chokes- not a match
4.5 and 4.0 Aux venturi's- not a match
All 4 starter jets 75-F5-a match
40 and 45 pump jets- not a match
And a collection of these:
Air correctors: Mains:. E-tubes
165 X 2 105 X 1. F24 X 2
170 X 2. 110 X 2. F27 X 2
175 X 2. 115 X 1. F30 X 4
195 X 4. 125 X 2. F36 X 2
200 X 2. 130 X 1
220 X 2. 132 X 2
140 X 2
These pics are the idle jets. The carbs had the shorter ones but there are several longer ones as well? Will these interchange?
Shorts:
.50 X 4
.45 X 2
Long:
.45 X 2
.50 X 2
.55 X 2
.60 X 2
.70 X 2

Where do I start and what do I try and collect as a starting point?
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Hi Cliff,

First goal will be to do matches. So you will need to do some changes about
30 and 32 chokes- not a match
4.5 and 4.0 Aux venturi's- not a match
40 and 45 pump jets- not a match

In theory, following Pat Braden's recommendations (I think it is him....)

Chokes
Most x19 owners I know of got 32 chokes (recommmended for 40 DCNF), but theoretically, 30 would be a more appropriate choice for a 36 DCNF. In the end, both will do and I would say, whatever you will find first.

Aux venturi
All the X19 DCNF,s I know of got 4.5.

Pump jets
Same here. All the X19 DCNF,s I know of got 45.

But since we are all talking about the "next size", same applies here, whatever you will find first.

Main air correctors: 75% owner I know got the 220. The other one got 185 (you don't have). In theory, these are "overkill". A set of 175 would do.

Main jets: Since you got a pair of 125, I would go with them. This is probably the ideal.

Emulsion tube: F24 is a popular size or F36. Look at this link:

On the idle jets size, I don't belive the 2 lenghts will do. Go with the same length you actually got. The .50 are what I used. But in theory the .40 would be the perfect size.

Also, remember that most of these carbs came from various other cars and were often "adapted" for their use in x19, so most are different. In fact, I haven't seen 2 cars with the same set-up. So a first approximate set-up should do, then if you want to max your tuning, you will have the chance to modify in function of the results.
 
The dual 40DCNF setups I've seen typically use 32mm chokes and 4.5mm aux venturis and either F24 or F36 emulsion tubes. Looks like you are half way there. I'm using #11 pump cams and .45mm pump jets. My mains are 1.30mm, air 2.20mm, idle .55. My needle valves are 1.75mm, and the idle air orifices are 1.613mm (measured).
 
Hi Cliff,

First goal will be to do matches. So you will need to do some changes about
30 and 32 chokes- not a match
4.5 and 4.0 Aux venturi's- not a match
40 and 45 pump jets- not a match

In theory, following Pat Braden's recommendations (I think it is him....)

Chokes
Most x19 owners I know of got 32 chokes (recommmended for 40 DCNF), but theoretically, 30 would be a more appropriate choice for a 36 DCNF. In the end, both will do and I would say, whatever you will find first.

Aux venturi
All the X19 DCNF,s I know of got 4.5.

Pump jets
Same here. All the X19 DCNF,s I know of got 45.

But since we are all talking about the "next size", same applies here, whatever you will find first.

Main air correctors: 75% owner I know got the 220. The other one got 185 (you don't have). In theory, these are "overkill". A set of 175 would do.

Main jets: Since you got a pair of 125, I would go with them. This is probably the ideal.

Emulsion tube: F24 is a popular size or F36. Look at this link:

On the idle jets size, I don't belive the 2 lenghts will do. Go with the same length you actually got. The .50 are what I used. But in theory the .40 would be the perfect size.

Also, remember that most of these carbs came from various other cars and were often "adapted" for their use in x19, so most are different. In fact, I haven't seen 2 cars with the same set-up. So a first approximate set-up should do, then if you want to max your tuning, you will have the chance to modify in function of the results.
The carb I received from Jim (Agnelli) had the shorter idle jets and I do have four so I'll go with those and will post to see if I can find what I need as a starting point with everything. I just want some place to begin and not have everything so far out of whack that I'm chasing my tail forever. I'll purchase an AFR gauge as well as a carb synchronizer to do things right.
 
The dual 40DCNF setups I've seen typically use 32mm chokes and 4.5mm aux venturis and either F24 or F36 emulsion tubes. Looks like you are half way there. I'm using #11 pump cams and .45mm pump jets. My mains are 1.30mm, air 2.20mm, idle .55. My needle valves are 1.75mm, and the idle air orifices are 1.613mm (measured).
Thanks Don, think I'll mimic yours
 
So if I'm reading all this clearly this is where I'll start and try to collect what I may need. Please correct me if I'm way off because once again don't want to waste time dicking around chasing Goblins.
32 Chokes
4.5 Aux Venturi's
45 pump jets
175 air correctors
125 main jets (based on Pat Braden)
Either F24 or F36 E-tubes
.45 idle jets
175 needle valve
11 pump cams
Starter jet 75-F5
Also, are the shorter idle jet with the longer holder for a different carburetor? Possibly for a 36 or a larger DCNF carb? As I mentioned the 40 DCNF I received from Jim had the shorter holder/longer jet so I'm assuming they are the correct fit for these ones and luckily I have 4 so that's what I'll go with. Advice on all the other items I mentioned would be a huge help to get started. Thanks in advance guys
 
Looks pretty good.
I have never seen the longer holders. I don't think they are from a DCNF.

I would choose F24 emulsion tubes. That is the "standard" for the X1/9.
The .45 idle jets will probably be too small. .50 or .55 is usually better.
With the smaller jet you will get a lean spot when transitioning from progression to main circuit. (Stepping on the gas when cruising on the interstate for instance).
Since you already have the 50s, use those.

You may have to change main jets and or air correctors when you optimize your jetting which is best done with a wideband O2 sensor.

You will need banjo type fuel fittings and matching hollow bolts to hook up your fuel line.
And the most important part, the interconnect linkage between the two carbs.
 
Looks pretty good.
I have never seen the longer holders. I don't think they are from a DCNF.

I would choose F24 emulsion tubes. That is the "standard" for the X1/9.
The .45 idle jets will probably be too small. .50 or .55 is usually better.
With the smaller jet you will get a lean spot when transitioning from progression to main circuit. (Stepping on the gas when cruising on the interstate for instance).
Since you already have the 50s, use those.

You may have to change main jets and or air correctors when you optimize your jetting which is best done with a wideband O2 sensor.

You will need banjo type fuel fittings and matching hollow bolts to hook up your fuel line.
And the most important part, the interconnect linkage between the two carbs.
Great Ulix, thanks!
 
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