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Discussion Starter #1
Are the venturis locked with a screw?
I have removed the auxiliary venturis easily, just with my fingers, but the venturis seems to be locked. They move about 1mm and then seems to hit something. (accelerator pump jets are removed) I can't see any screws at the bottom.
Can I use more power without damage?

Alvast bedankt,
Lex
 

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Richard Jemison
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Venturi

If the Aux venturi has a spring to locate it, then the venturi`s will slide out as well.

On larger 45 DCOEs they are both positioned by pointed bolts in the bottom of the carbs.
 

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But you have to take it out to see if there is a spring......
More simply,
40 dcoe has a flat spring in a groove. It will pull out.
 

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Whoa! 44-45's have the main air correction screws over the throats. These MUST be removed for the main choke, not secondary, to slide out. Force will bend the tip of the needle and cut a groove in the choke exterior.
The spring referred to is on the SECONDARY (low speed) choke. Those slide out normally.
In the picture below of a pair of freshly restored 40DCOE44&45's, note the grey plastic cover over the air-correction needle over the throat, below the pump jet brass cover. Remove the plastic caps, loosen the 6 mm lock nut and unscrew the needle. There are 4, one over each throat. Needles out, the choke slides out.
 

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That's the trick!
 

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Discussion Starter #8
Thanks to everyone, it was that air by pass screw with that plastic top.
Thanks for the quick responses,

Lex
 

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Any time Lex.
 

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I'm glad I came across this thread. I was confused having watched a video featuring DCOE45s that had a different type of fixing underneath for the venturi whichis absent on the DCOE40s

I will take a look mine as I'm going from 30mm to 32mm. The previous owner of mine just carried the 44/45 carbs straight across from the original 1600 engine when he fitted a 2000. I've already upgraded the jets
 

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I tried and failed to remove my venturis at the weekend.

With the carbs on the engine and with the air filter, pump jets and idle by-pass screws removed, it was easy to remove the auxilary venturis. However, I couldn't get the main venturis to move at all. Stuck in place as they have been in there for 40 years or am I missing something?
 

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Did you REMOVE the primary correction jets, (4) one over each throat? The needle of each passes through a hole in the primary choke. Unless REMOVED, not just loosened, the primary chokes are locked in place.
See photos. #2 shows one of these. If they are out, try removing the pump jets, and then LIGHTLY tap the primary choke "further" into the bore to loosen any gummy deposits holding it in place. Then try removal. Still won't come out? Spray down the throats with carb and choke cleaner, tap (LIGHTLY!) again and try removal.
If that doesn't do it, send me a PM with your e-mail address, and I'll discuss more drastic approaches.
 

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If that fails, send me a PM with e-mail contact, and we will go further.....
 

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[/url]Choke Puller by Malcolm Bull, on Flickr[/IMG]Success - well nearly.

My buddy Chris came up with an improvised choke puller tool featuring some threaded bar and a rubber bung. Using an adjustable spanner as a lever and a block of wood as a fulcrum and to protect the carb body, he managed to pop them out. Check out the deposits which were the cause of them sticking in.

I cleaned most of the deposits in the bore with carb cleaner and slide 3 of the 4 new 32mm chokes in to place. the 4th one is being stubborn and sticking before its fully home, so I'm going leave the bore soaking over night
 

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I'm glad I came across this thread. I was confused having watched a video featuring DCOE45s that had a different type of fixing underneath for the venturi whichis absent on the DCOE40s

I will take a look mine as I'm going from 30mm to 32mm. The previous owner of mine just carried the 44/45 carbs straight across from the original 1600 engine when he fitted a 2000. I've already upgraded the jets
Hi Malcolm,

It's exactly the same for me: 44/45 carbs on my 2000 GTV instead of 76/77. Did you notice a difference when you rejetted it to standard? what's about 32 venturis?

Regards

Ludo
 

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On reassembly, I use a brass polishing wheel on the contact surfaces (mirror shine) then spray with slip plate graphite coating it dries like paint. It has many uses for automotive resto work $8-10 bucks a can....I even use it to coat cast headers after bead blasting,
 

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I was quite surprised that the previous owner had just carried across the carbs without changing the jets or venturis. I figured that updating the carbs with 32mm venturis and 135 mains would ensure that the power was about right and more importantly that the mixture at full throttle would be safe (i.e. correct degree of richness). 34mm venturis is also an option.

Also, changing the idle jets would mean I get the correct mixture at part load for good driveability and fuel consumption.

I have had some trouble with the engine stumbling at around 2000rpm - when I got it but also after the updates. Running richer jets helps - 55F8 or 50F9, but perhaps that means my carbs need a good clean. More tinkering required.
 
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