1974 dual carbs, central idling unit and cut-off solenoid

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Birdibus
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1974 dual carbs, central idling unit and cut-off solenoid

Post by Birdibus » Sun Apr 13, 2008 10:43 am

I'm new at this, and need everyone's guidance. During a recent visit by Colin he diagnosed my problem to be an inoperational central idling unit and a missing cut-off solenoid. I have OG Solex carbs. There has been some rebuilding and rebushing done to them in recent times, but apparently whatever part was needed for the CIU was never obtained.

I have lots of black soot on the bumper. Colin can explain more. All I know is he fiddled with it for a long time, and my hair and clothes were thouroughly poluted by the time he was done.

What is my next step? Do I need to be searching for some hard to find OG part? Do I need to contact a carb expert? Hopefully, once the CIU is repaired, we can balance the carbs as they were designed to operate.

thanks!
71 bus, 74 westy

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Amskeptic
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Re: 1974 dual carbs, central idling unit and cut-off solenoi

Post by Amskeptic » Mon Apr 14, 2008 8:32 pm

Birdibus wrote:I'm new at this, and need everyone's guidance. What is my next step? Do I need to be searching for some hard to find OG part? Do I need to contact a carb expert? Hopefully, once the CIU is repaired, we can balance the carbs as they were designed to operate.
As per our noxious conversation in the haze behind smog o'bus, we need to ascertain what jets you have installed in the carbs, we need to make sure all required parts are present and operating. That is the very next step. And since we have to pull the carbs to see what jets you have, two rebuild kits (one for the left side and the other for the right) are called for as well. A careful cleaning and adjustment and you're on your way.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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karl
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Post by karl » Mon Apr 14, 2008 8:54 pm

Talk to Keith. He rebuilds them. You can contact him here: http://www.thesamba.com/vw/classifieds/ ... ?id=528078

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Sluggo
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Post by Sluggo » Tue Apr 15, 2008 6:57 pm

karl wrote:Talk to Keith. He rebuilds them. You can contact him here: http://www.thesamba.com/vw/classifieds/ ... ?id=528078
Keith Rocks! Seriously!
:vwgauge420:

1977 Bus with Sunroof - "Lucky '77"
2000cc Type IV w/Dual Weber 36s,
Aircooled.net SVDA w/Compufire,
Redline Weber Fuel Pump,
Holley Regulator,
Half Ass Brush & Roller Rustoleum Paint Job,
Incomplete Custom Interior,
Dual Batteries,
Crunched Slider Door.
------------------------------------------------------

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spiffy
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Post by spiffy » Tue Apr 15, 2008 8:06 pm

Another happy customer of Keith's right here.
78 Riviera "Spiffy"
67 Riviera "Bill"

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Birdibus
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Re: 1974 dual carbs, central idling unit and cut-off solenoi

Post by Birdibus » Wed Apr 16, 2008 1:59 pm

Amskeptic wrote:we need to make sure all required parts are present and operating. That is the very next step. And since we have to pull the carbs to see what jets you have, two rebuild kits (one for the left side and the other for the right) are called for as well.
Colin
ummm, I meant, what parts should I be looking for or ordering? Of course I need a cut-off solenoid for the central idling unit. But what about the unit itself? A rebuild kit? A replacement? Do we know?

When do you think pulling the carbs should take place? Are you going to be in soCal before August?
71 bus, 74 westy

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keifernet
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Post by keifernet » Thu Apr 17, 2008 10:08 am

Colin is extremely knowledgeable about ( well so many things but...) the dual carbs etc. If you can wait and sign up for him to do the rebuild when he's in the area then that's great.

I wonder just which solenoid(s) you have that are bad... the air cutoff of the idle pilot on the left carb? or what about the one on the right carb?

Image

Image

Also I have seen very very few that the throttle shaft "bushings" ( not much of a bushing from the factory.... on little bronze alloy ring and plastic insert) were not worn out on.

Image

In the mean time ( if it is not your driver) you could send me just the throttle plates to rebush and then have Colin go through the carbs if you schedule him as part of your day with him.... or I could also re do the carbs and get them back to you at just the right time for him to install and tune/set up that day as well.

I am not trying to ram anything down anyones throat here... or invade on what Colin wants to or might have plans to do for you... just offering up my services if wanted or needed.

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Birdibus
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Post by Birdibus » Fri Apr 18, 2008 11:09 am

I find in my service records about 7000 miles ago an entry for: overhaul carbs and rebush throttle shaft. The parts list includes 2 rebuild kits and 4 bushings. That's not many miles ago, but it is actually more than 10 years ago. The engine blew shortly afterward and the bus sat unused for many years. It's been a long slow process sorting out issues since the rebuild. Are there any parts in a carb rebuild kit that can go bad with age despite disuse?

The central idling unit is missing it's solenoid. The other two solenoids on the right and left carbs are still there.

Once the solenoid is replaced, what are likely to be problems with a central idle unit? Or maybe (hopefully) the solenoid is the only part I need. Still, I need an expert to get the whole system adjusted.
71 bus, 74 westy

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keifernet
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Post by keifernet » Sat Apr 19, 2008 7:23 pm

Birdibus wrote:I find in my service records about 7000 miles ago an entry for: overhaul carbs and rebush throttle shaft. The parts list includes 2 rebuild kits and 4 bushings. That's not many miles ago, but it is actually more than 10 years ago. The engine blew shortly afterward and the bus sat unused for many years. It's been a long slow process sorting out issues since the rebuild. Are there any parts in a carb rebuild kit that can go bad with age despite disuse?

The central idling unit is missing it's solenoid. The other two solenoids on the right and left carbs are still there.

Once the solenoid is replaced, what are likely to be problems with a central idle unit? Or maybe (hopefully) the solenoid is the only part I need. Still, I need an expert to get the whole system adjusted.
I doubt rebushing would go bad in 7K and 10 years sitting... but for sure a good wiggle on the shafts and inspection to make sure they used "proper" bushing materials is in order.

Otherwise YES sitting for all those years to me is INSTANT rebuild... the parts( any rubber diaphrams/o-rings etc) just cannot survive sitting that long with old fuel or otherwise and aging... crud dried up in the carbs...

I tear down carbs that have been sitting for years/decades every week and find the parts totally crusty and old crap dried up in every possible orifice...

Only a meticulously "pickled"/planned storage might could survive that length and even then I would be inclined to tear the carbs down and see.

If your missing the bigger solenoid in the top pic I posted then what is plugging the hole?

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Amskeptic
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Post by Amskeptic » Sat Apr 19, 2008 11:49 pm

keifernet wrote: If your missing the bigger solenoid in the top pic I posted then what is plugging the hole?
That is the question. It is a butcher job in there, Keith. Might have been JB Welded. That is why I wanted cannibal parts so I could somehow land on my feet with all of these unknowns yet to be sorted.

I requested of birdibus to procure a central idle solenoid, two cut-offs for the carbs, jets for a 74, and perhaps a couple of used carbs, then we could make things functional and correct. HOWEVER, she needs the car, it is not driving well because of filthy rich running and I cry in my beer every night at the thought of her being cast to the wolves of savage ignorance yet again as she tries to find someone who knows what the hell they're doing without further butchery. I cannot be there until August.
Colin
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

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keifernet
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Post by keifernet » Sun Apr 20, 2008 8:55 am

Amskeptic wrote:
keifernet wrote: If your missing the bigger solenoid in the top pic I posted then what is plugging the hole?
That is the question. It is a butcher job in there, Keith. Might have been JB Welded. That is why I wanted cannibal parts so I could somehow land on my feet with all of these unknowns yet to be sorted.

I requested of birdibus to procure a central idle solenoid, two cut-offs for the carbs, jets for a 74, and perhaps a couple of used carbs, then we could make things functional and correct. HOWEVER, she needs the car, it is not driving well because of filthy rich running and I cry in my beer every night at the thought of her being cast to the wolves of savage ignorance yet again as she tries to find someone who knows what the hell they're doing without further butchery. I cannot be there until August.
Colin
I have collected quite a few cores so if she/you need a lefty top with good threads(sent ahead of time for when you get there) for that solenoid intact or other stuff LMK.

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Birdibus
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Post by Birdibus » Mon Apr 21, 2008 10:00 am

I requested of birdibus to procure a central idle solenoid, two cut-offs for the carbs, jets for a 74, and perhaps a couple of used carbs
Oh good! There's the list I needed.

Lots of unknowns... OK, I can understand that. The parts need to be here before your visit, so we need to be overprepared.

I already have the right and left cut-offs on the vehicle, to jog your memory. Did you determine them to be questionable? Do I need new ones, or do I need to look for OG used?

Are jets available new, or do I want refurbished or used parts? Which jets?

So, the central idling unit is part of the left carb? Sorry, keifernet, I don't know what I'm looking at yet in the photos. I haven't yet figured out where the CIU is located... sigh... steep learning curve.

Yes, then, two new rebuild kits it is.

If someone tells me it is harmful to drive the bus as it is, what is the danger? I will switch to driving the 71 if necessary. I would like to fix the rust in the battery tray area when I change the battery, but will prioritize the job if I need to revive the older bus.
71 bus, 74 westy

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Birdibus
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Post by Birdibus » Wed Apr 23, 2008 11:57 am

Let me answer my own dumb question... yes, the central idling system is part of the left carb... I see it here in Bentley Fig. 5-26.

Engine damage from driving with a rich fuel mixture?... I'm guessing I ought to stop driving ASAP. Or no?
71 bus, 74 westy

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