Tuning carbs - need help at step 1 - idle speed

its behind and between the two forward carbs. Release the lock nut, and turn the cable housing which pulls the throttle cable forward and raises the idle.

This is a good one to take your time with, its a finesse job.
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play with it before starting car, and observe how all the linkage works without the car running, that will save you sweat and fume

 

I know I should refrain from answering since I don't own a carb Ferrari BUT...that looks like a standard bowden cable. The nut against the manifold is the lock nut, the nut against the cable housing moves the housing toward/away from the mounting point and thus tightens/loosens the cable and, thus, changes the carb opening.

Loosen the lock nut and then turn the larger nut out (counter clockwise)to increase idle or in to decrease idle. It looks like it's close to all the way in at the moment. The entire end of the housing/threads look like they could use cleaning/lubricating. I suggest you disconnect the cable, unscrew the housing all the way and put some antisieze on the threads and then proceed with adjustment. You might consider actually lubricating the cable itself, from the accelerator pedal end. But that's a lot more work!

 

Let me see if I can be helpful.

mike996 is correct in saying the lock nut is closest to the valve cover.

The nut farther away from the valve cover is attached to the cable cover by a swivel joint and rigidly attached to the threaded shaft going into the valve cover boss and this nut controls the path length the internal cable follows. Lets now call this the adjusting nut. So, if you make the cable path longer, the cable pulls on the throttle bellcrank and linkage, at the carb end, because the cable itself doesn't change in length. The screw thread in the valve cover and on the cable cover is a normal right hand design.

When viewed from the back of the car, turning the adjusting nut clockwise will increase the cable path length, making the cable pull the carb linkage such that the throttle will open. So this one adjusting nut can be used to increase or decrease the throttle opening of all carbs simultaneously. This is effectively a vernier throttle pedal and is very useful for enabling synchronization of the carbs. If the idle rpm is too high, turn the adjusting nut counterclockwise and the throttles on all shafts will close the same amount.

Synchronization occurs elsewhere on the linkage. Each time a synchronization adjustment is made, it's good to go back to the adjuster nut to reset the engine idle speed to a nominal 1000 rpm.

Bill

 

You should check the condition of all your fuel lines while you're in there. I see a lot of 'hide-the-condition' braided fuel line. You don't want to find this
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Congratulations! I have this to do soon and based on your challenges I am not looking forward to it. I do not even have the benefit of being the person that took it apart. Ugh.

 

Nice Work!

Please post a picture of your " factory tool" and what plugs are you running?

 

Thank you!

 

Not necessarily. This is what I use. The shorter extension for the front bank and a piece of snug fit hose once the plug is loose.

Best Regards
Martin
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I use short extension and telescopic magnet tool. Drop socket in. Drop extension in. Fit extension on socket and plug. Fit wrench on extension. Twist off. Pull wrench. Pull extension off socket with lateral force while pulling. Use magnet to pull socket and plug. Sounds like a bunch of work but goes amazingly fast and is done all by feel. Way better than factory tool.

Caveat I am 6-2 with long arms and big hands which helps. I do this with lid on working from the front. I can reach around the lid and hand myself tools and plugs.