Centermount, progressive, 2BBl carb on Type IV doesn't suck

Jeff Geisen · Posted: Mon Feb 26, 2007 8:10 pm Post subject:

... I agree with those posts above that say much of the blah blah blah is coming from the un-informed and inexperienced. I don't have a dog in this fight, thank God. I started out with the F.I., and had the frustrating experiences I read of on here every day... the thing would run beautifully, or not at all. And the thing was, I never knew when it would start playing games.

I run an upright engine with dual Solex carbs, the only carb that is designed to run on a VW... any other brands are designed for water pumpers. Now, I realize that other brands can and do run correctly on ACVW applications, but it is no accident. It is all in the set-up. Even with Solex, the jetting must be very close to spot on as far as jet size and accelerator pump discharge, humidity and your individual elevation. It's a labor to achive the zen, but it can be done.

What has worked for me is trial and eror. Get in there and dig and reason and eliminate the variables. If I were to wheel a late bay, It would defiately be carbureted, 'cause I don't have the ablity, time, patience, or the resourses and funds to chase all those ghosts in the antiquated Bosch F.I. systems. Old 30 something year old wiring, corroded grounds, and all the one year only parts... pleah!

Keep working with your progressives. Jet, tweak, massage and learn from your experience.

Bear in mind that much of the information, theory and advice given here on this forum is worth about what you pay for it. I have learned to check a persons credibility by simply viewing the posters gallery pictures. If they show you pictures of thier travels, the chances are pretty good they are actually bus drivers, instead of merely bus owners. Peace out.
_________________
... I actually drive my bus, and I maintain it myself, it runs fine. I drive it all over the place. Really, check my gallery.

I John 4:20, 21 NKJV

trevize1138 · Posted: Mon Feb 26, 2007 8:46 pm Post subject:

OK, all I did, indeed, need to get it started again was just wait another couple hours. Must have been flooded because it started up right away. And when it did start it was roaring at high RPM! I turned the fast idle cam screw in quite a bit more so it would actually move the throttle when the auto choke is on. Imagine that.

Now, as far as I know, my posts in this thread represent the ONLY on-line record of how to calibrate a Solex 2 barrel, progressive carburetor! (I'd love nothing more than for someone to be smart-@ssed enough to say "You're wrong, here's a link to a PDF with detailed info.") I seem to have been right about the idle mixture screw and the idle speed screw locations.

Once I dialed down the auto choke so it would open up totally after only a minute or so I was able to successfully get the idle under 1000 rpms and smooth. The carb must be jetted slightly wrong (wild speculation from someone who's only read a teeny bit about jetting) because I had to have the mixture screw about 1/8 turn out from bottom and the speed screw about 1/4 in after touching. So, yeah, barely any fuel or air goin' in during idle and it's sill 950-1000 RPMs.

If I back the speed screw all the way so it's either just touching or not touching at all and the mixture screw in all the way the motor sputters and dies as it should. The next thing I need to do is reposition the ball joint that connects to the barrel clamp attached to the throttle cable. There are several holes along the throttle arm and if I attach it one hole further to the back of the bus then it'll open the secondary throttle all the way when the pedal's on the floor. Currently that's impossible due to the position. I'm guessing performance will be even better once that's done Smile

.

The thing ran great before doing this and now it runs even smoother and easier!
_________________
'72 Ghia Coupe
'72 Westy Hardtop
'72 Super Beetle (long dead and gone!)
http://druckenghia.blogspot.com/

Jeff Geisen · Posted: Tue Feb 27, 2007 4:59 am Post subject:

Way to go, Bro! That's what I'm talkin' about!

You are not only learning, and having a rewarding experience; you are gathering useful and practical information for both you and the readers of this thread.

You write well too.
_________________
... I actually drive my bus, and I maintain it myself, it runs fine. I drive it all over the place. Really, check my gallery.

I John 4:20, 21 NKJV

trevize1138 · Posted: Tue Feb 27, 2007 6:49 am Post subject:

Thanks, Jeff. That English degree finally pays off! Razz

Here's a picture I snapped of the left side of my carb a while ago when I was asking for help in the Performance/Engines section on the carb:

Image may have been reduced in size. Click image to view fullscreen.

Image may have been reduced in size. Click image to view fullscreen.

As you can see, I incorrectly wondered if that screw I have circled is the idle adjustment screw. It plugs into the auto choke but I have no idea what it does. Perhaps just some kind of fine-tuning so you don't have to loosen the three housing screws and rotate the drum to adjust?

Below that you can see the large cam-shaped throttle arm and two of the multiple mounting holes. The ball joint is attached to the 3rd hole from the right (cropped out of photo at bottom). When I have it floored there's a straight line from the cable to the ball joint to the throttle shaft but the secondary's barely open. So, as you can see, if I move it one or two holes to the right it will pull the throttle open further.

Also, from this perspective, the idle mixture screw is on the other side of the carb, to the left and at the base. It's on the other side of that hole you see to the left of the throttle arm. You can also see part of the throttle arm resting on the end of the idle speed screw just above the throttle shaft. About four threads of that screw are showing here.

Finally, notice how nearly vertical the word "Solex" is on the auto choke =) I made that horizontal and even tipped a bit the other way. WAY smoother driving.[/img]
_________________
'72 Ghia Coupe
'72 Westy Hardtop
'72 Super Beetle (long dead and gone!)
http://druckenghia.blogspot.com/

Duncwarw · Samba Member Joined: August 25, 2003 Posts: 3096

FWIW, I mounted my progressive "right way 'round" and just moved the cable over to the right.

It seems like a big pain to have to adjust the mixture and idle up against the bulkhead.

To keep from fraying the cable, I glued in a water feed pipe for a toilet.
It's flexible enough to bend just right by hand and has a nylon washer on the large end which is now up against the tin where the cable enters "the room".
_________________
“To find yourself, think for yourself”
Socrates, 470 BC - 399 BC

trevize1138 · Posted: Tue Feb 27, 2007 8:36 am Post subject:

trevize1138 · Posted: Tue Feb 27, 2007 9:20 am Post subject:

FYI:

I've added this thread to the "Helpful Threads" sticky:

http://www.thesamba.com/vw/forum/viewtopic.php?t=165001

A link to the popular Webber progressive thread appears to have been linked there, too.
_________________
'72 Ghia Coupe
'72 Westy Hardtop
'72 Super Beetle (long dead and gone!)
http://druckenghia.blogspot.com/

trevize1138 · Posted: Tue Feb 27, 2007 1:18 pm Post subject:

Ooh, someone on eBay is selling the same carb body that's part of my system:

http://cgi.ebay.com/ebaymotors/SOLEX-CARBURETOR-34...0293QQrdZ1

Image may have been reduced in size. Click image to view fullscreen.

_________________
'72 Ghia Coupe
'72 Westy Hardtop
'72 Super Beetle (long dead and gone!)
http://druckenghia.blogspot.com/

Jeff Geisen · Posted: Tue Feb 27, 2007 1:37 pm Post subject:

... you oughta invest in that, Chris!
_________________
... I actually drive my bus, and I maintain it myself, it runs fine. I drive it all over the place. Really, check my gallery.

I John 4:20, 21 NKJV

keifernet · Posted: Tue Feb 27, 2007 2:00 pm Post subject:

SixVolt · Posted: Tue Feb 27, 2007 2:21 pm Post subject:

Anyone have any photos? It would sure help to understand much of what is being discussed here, if someone could document the mixture/air screw locations, jet locations and cable/fuel hookups. Just a thought.
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It's me, Sean
1957 Oval (36 horse 6 volt)
1959 SO-23 Westfalia (1600SP 6 volt)
1978 Transporter (6 volts too many)

keifernet · Posted: Tue Feb 27, 2007 2:45 pm Post subject:

Petervw · Posted: Tue Feb 27, 2007 4:28 pm Post subject:

the 10C/50F is the about the correct number to keep in mind when ANY carburetor needs to have some warm air drawn into the system(even my old '86 carb subi is like that..an old Hyundia with a carb I recently saw at the scrapeyard had a "flap" to be closed manually be lifting the hood ...although , unlike the subi or hyun... I don't know if it is possible to draw only hot air without hurting the aircooled...

SixVolt · Posted: Tue Feb 27, 2007 4:56 pm Post subject:

busman78 · Posted: Tue Feb 27, 2007 6:26 pm Post subject:

The sticky should be for all progressives. They all require similar tuning technique, they all take the same trash can talk from nay-sayers, and why limit the conversation to "Solex" only or "Weber" only, what do you do with the Holley version? Create another Sticky?

keifernet · Posted: Tue Feb 27, 2007 7:42 pm Post subject:

1977_L63H_P27 · Posted: Tue Feb 27, 2007 8:25 pm Post subject:

About 10 or 12 years ago I bought a '72 dual-carbed type IV engine for my wifes '73 Bus. Needless to say the carbs sucked so much air around the throttle plate shafts, that she idled at over 2k rpms. So I called the local VW parts house and asked for a remedy. They suggested the progressive Weber kit and they had the specific one for that engine. I never had to make the first adjustment. It started and ran perfectly right out of the box. I even took it to my VW mechanic, a man with 30 yrs. of air-cooled experience, who confirmed my thoughts. He told me that I hit it lucky with that carb, as most had to be fine tuned.
I live in north-east TN. right near the VA. and N.C. borders. We have plenty of humidity and fairly cold winters. Two years of driving and never an ice up or a sputter. I know I'm lucky, but I wanted to let y'all know that there are some good progressive carbs out there. Peace!
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trevize1138 · Posted: Wed Feb 28, 2007 6:37 am Post subject:

I propose a theory:

I have yet to see someone explicitly state the following:

keifernet · Posted: Wed Feb 28, 2007 9:05 am Post subject:

trevize1138 · Posted: Wed Feb 28, 2007 9:18 am Post subject:

I can't help thinking that there's also just the fallacy of pure theory. In theory any centermounted carb on a Type IV would not run right and be prone to icing. It's a logical hypothesis, but in actual practice if it's set up correctly that theory seems to have a few holes in it.

A good analogy would be something I see in my other hobby of off-road cycling. In theory a full-suspension, lightweight, 27-speed bike would perform better than a totally un-suspended, steel framed singlespeed bike. Yet, in actual practice, I've only been passed by one rider who had a full-suspension, full-geared bike while on my full-rigid singlespeed and he only beat me in that 30+ minute race by 10 seconds.

Between nearly identical bikers the difference in performance between the two bikes is either non-existant or minimal. Plus, between races all I have to do is clean and grease my chain, check the brake adjustment and final chain tension. I don't have to mess with derailleurs, an extra set of cables, adjusting shifters, changing shock damping oil ... Smile

Simplicity, whether it's a single carb or a single speed, has definite advantages.
_________________
'72 Ghia Coupe
'72 Westy Hardtop
'72 Super Beetle (long dead and gone!)
http://druckenghia.blogspot.com/

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Centermount, progressive, 2BBl carb on Type IV doesn't suck
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