How do I remove the Solex 30 PICT-2 metering screw?

[Alpha_Maverick]

Those who know what I'm talking about:

How the hell do you get that thing out? I'm trying to lean out my idle/transition circuit, but I can't get lower than a 54 idle jet before my idle screw is worthless. I need to get more "fuel" (it's an air/fuel emulsion, coming out of the idle jet) into the engine with the throttle closed.

TL;DR

How do I remove the metering screw from hell? I'd like to do as little damage as possible.

THANKS!
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[Alpha_Maverick]

Nobody knows how to get it out? I know that several of you on here have done it!

I got a cheap set of hollow ground screw driver bits, and they bent before the screw turned. I'm being very careful to not damage the screw.

Is there anything binding against or blocking that screw from turning? Do I just need to get stronger dedicated screw drivers, and twist until something breaks?

I know somebody on here has experience with this... Should I repost this in the 68+ type I forum?
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[earthquake]

Can you post a picture of the screw you are talking about? Are you talking about the A/F mixture needle screw? mine came right out, its in a steel insert in the body of the carb.

Casey
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74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
95 Chevy C3500 dually
98 Ford E150
Link to Kelly J. Nolte 3/20/53 - 11/6/08
https://time-zonelabs.blogspot.com/p/about-kelly.html
DEATH TO CHINGERS!
[From a military recruitment poster in the novel "The Stainless Steel Rat" By Harry Harrison]

[williamM]

I've had that insert spin in the carb body--very covertly- try some blaster and let it soke for a few days then screw it in before trying to un screw it-
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[wcfvw69]

I've played with a lot of Solex 30 PICT-2 carbs and have never had to play with the fuel metering screw on any of them. It's a factory set and Bentley and VW said not to adjust it.

What jets are you running for a main and air correction on what size engine? Single port/dual port?
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[Alpha_Maverick]

Not the mixture screw. That one moves fine.

This one:

#27 in this picture:

I'm not dealing with the main or air correction circuits. I am trying to lean out my transition/idle circuit. The main circuit is not coming into play at idle. Please do not tell me to rejet anything. I want to adjust the metering screw. Yes, I know they say not to adjust it. I'm doing things... differently.

Thank you for your willingness to help, and I hope someone shares how they did it. I know a few of you guys have done it.
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[wcfvw69]

http://volkzbitz.com

Contact this gentleman. He's the Solex rebuild specialist. The other person is the author of this thread. Maybe PM him.

http://www.thesamba.com/vw/forum/viewtopic.php?t=185095

His name is Andy and he's also well versed in Solex carbs.
_________________
Contact me at [email protected]
Follow me on instagram @sparxwerksllc

Decades of VW and VW parts restoration experience.
The Samba member since 2004.

**Now rebuilding throttle bodies for VW's and Porsche's**
**Restored German Bosch distributors for sale or I can restore yours**
**Restored German Pierburg fuel pumps for sale or I can restore yours**
**Restored Porsche fuel pumps or I can restore yours**
**Restored Porsche distributors or I can restore yours**

[Alpha_Maverick]

excellent! Thank you!
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[gt1953]

Yep send it Volkzbiz he will One of the top shelf solex carb guys right now.
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Numbers Matching VW's are getting harder to find. Source out the most Stock vehicle and keep that way. You will be glad you did.

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[Alpha_Maverick]

So I emailed glutamodo, and he didn't have any ideas. I then emailed volkzbitz, and he said that the manufacturer had put some form of threadlocker on it. He suggested that I try various solvents on the screw, get a better hollow ground screwdriver set, and try to work the screw back and forth until it works loose. He also suggested applying some amount of heat. Perhaps a butane torch. Great suggestions, now for a new question:

What kind of solvents would normally be used on thread locker compounds? This stuff feels about equivalent to red flavor.
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[earthquake]

Use a heat gun, no flame that way.

Casey
_________________
74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
95 Chevy C3500 dually
98 Ford E150
Link to Kelly J. Nolte 3/20/53 - 11/6/08
https://time-zonelabs.blogspot.com/p/about-kelly.html
DEATH TO CHINGERS!
[From a military recruitment poster in the novel "The Stainless Steel Rat" By Harry Harrison]

[Alpha_Maverick]

Alright, I tried the solvent (everything I had, from denatured alcohol to goo gone) and heat (started low, and worked up to a butane torch right on the screw), to no avail. I took a bunch of pictures, and have a question *after* the pics and their descriptions.

Here we go...

Here is the screw I'm trying to adjust/remove:

Yeah, it's a little mangled, at this point, but it's still in decent shape, considering how much torque I've put on it. The plug to the left of the screw is, I think, a passage from the idle well to the transition ports. The round thing going to the left of that plug is the idle well. Just out of frame on the left is the idle jet.

In this picture, you can see how that screw lines up with a bunch of passage plugs:

In this pic, you can see a bunch of plugs, and bushing into which the idle mixture screw fits:

Here's a view of those same plugs, but I can use this to describe what goes to what:

*The Far left plug is the idle well. It leads up to the idle jet. The "metering screw" and the plug on the side both lead into this passage.
*The center plug looks like it leads to the transition ports (seen just above the throttle plate in this pic). This passage, I think, is fed by that side plug. Without pulling the plug, I won't know for sure.
*The plug to the right of the center plug is a passage that feeds the idle mixture screw (which is to the right). I checked the depth of the idle mixture screw hole, by pushing a small wire down it (L-R in this pic), and it bottomed out right at the left edge of this plug, so that is where the mixture screw gets it's fuel.
*The next plug to the right goes down to the idle mixture port (seen directly below said plug). I'm fairly certain that this port is ONLY fed by the idle mixture screw. There is a passage (vertical in this pic) connecting the idle mixture screw to this port.
*The next plug to the right (another big one) is the vacuum advance passage. You can't see the vacuum advance slot behind the throttle blade.

In this pic, you can see the mixture screw bushing, and how it lines up to those ports/plugs:

Here you see the mixture screw side of the carb. Note that there are no fuel passages which attach to the mixture screw:

Now comes the dissertation.
I think I want to remove the leftmost plug, and the plug to the right of center. This will give me a better understanding of how the passages connect, and how the mixture screw is fed. My question is: HOW? Do I use a similar method as the oil gallery plugs in the block? Are these thin walled like the oil gallery plugs, or are they solid chunks of metal, dripped into the passages, to seal them? If the latter, do I drill them out, or pull them?

After I get the plugs out, I should be able to better come up with a way to remove/adjust/bypass the "fuel metering screw." My theory is that the "fuel metering screw" actually restricts the feed to the idle mixture screw, preventing you from using it's full adjustment range. If this is the case, then all I have to do is break or drill out the "fuel metering screw" and plug the opening to the outside. This would allow the idle well to free flow to the idle mixture screw, and would allow me full range of adjustment.

I could be wrong about this, and that is why I need to pull a couple plugs before I make any permanent modifications. Thoughts? Ideas?

Thanks!
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[VolkzBitz]

The plugs are a soft metal that are maybe 2 or 3mm deep. You will have to drill them out. Im not sure exactly what you are trying to achieve, but to be honest, I wouldn't mess with the screw.
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Quality VW Solex carburetor restoration
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Der Vergaser Meister

[Alpha_Maverick]

Thanks for the heads up! Do you have any pics or knowledge of the passages beneath said plugs, to save me the time/trouble?

My goal is to lean out the transition from the idle circuit. I know this is done by changing the idle jets, but when you lean out the idle jet, you have to increase the "fuel" flow through the idle mixture screw, because it's actually an air/fuel emulsion. With the "fuel metering screw" in it's factory position, you have a very limited range of idle mixture adjustment, and I'm trying to increase that, so I can further lean out the transition circuit, without having a super-lean idle.
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[VolkzBitz]

Does this help?
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http://volkzbitz.com
Quality VW Solex carburetor restoration
[email protected]

Der Vergaser Meister

[Alpha_Maverick]

That does, but it creates more questions than answers...

The plug which is visible in your pictures, if I'm looking at it right, lies between the idle well and the passage that feeds the transition ports. I can't understand how that could possibly work. If that plug is indeed in that location, then the metering screw would not actually control anything.
ETA: Eureka moment. That "plug" is the metering screw! SMH


Also, is the right half of the picture just showing the other half of the passage feeding the transition ports, or is it another passage? Either way, the lower hole is how the metering screw feeds the idle mixture screw, right? What is the upper hole for?

Do you have any more pictures, or information? Thank you very much for what you've provided!
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[Alpha_Maverick]

Just another bump, in hopes that VolkzBitz will answer again.

Looking closely at your picture, and comparing it to mine, it looks like the upper passage on the right is very close to being in line with the idle mixture screw. Do you know if it is? Is that a hole between the passages? Do you know the diameter? I'm just trying to decipher exactly how the system works, and if there are any "gotchas" to my plan.

I have mostly decided to put the carb in a vice in a drill press and drill out the fuel metering screw, and replace it with a set screw that only reaches the first wall of the transition well. This will completely bypass that metering screw, giving me full available flow to the idle mixture screw. I know I'll need to be careful, but that shouldn't be a problem, if I get my machinist coworkers to help.
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[VolkzBitz]

The upper hole on the right is where the end of the mixture screw comes through.
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Quality VW Solex carburetor restoration
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Der Vergaser Meister

[Alpha_Maverick]

Since I've got the engine torn down, I convinced a machinist at work to put the carb in his mill, and drill out the screw precisely, then thread it for a plug. Here's the result:

You can see the idle jet well, the transition well, and the opening that leads to the idle mixture screw and (eventually) the idle mixture port.

I'll update on the behavioral results once I get the engine back together. I'm expecting to be able to run a much leaner idle jet, with commensurate city gas mileage improvement.
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[Alpha_Maverick]

Forgot to show the leftovers of the metering screw, for those that care.

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