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hi guys, first time poster, long time reader.
I've read another's post regarding adjustments for this carb (very enlightening). my problem may be a bit different, but I'm very very mechanically challenged.
When i start my 71 opel gt, the idling is way too low to the point of stalling. After driving a short while after downshifting and coming to a stop (at a light let's say), the car is revving incredibly high. I don't know how much more info you need, but does this sound familiar?
 

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sorry its took so long, work gets in the way. i read a few more posts and one about the brake booster hose caught my eye 'cause someone years ago said i had a leak there, so according to the post here you press the brake pedal down till firm and crank the engine, if the brake pedal gives a little there is no leak, so apparently there's no leak there because it did give a little (if i understood the post correctly!) I'm trying to make heads or tails out of the drawings and stuff regarding the carburetor and to tell the truth I couldn't tell a vacuum tube or hose from a garden hose can you take me by the nose about this vacuum leak stuff? Would a picture of my carburetor help??
 

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Solex cold idle problem

Your problem may indeed be a vacuum leak of some sort, but I'd check the setting of the choke when the engine is cold FIRST!

While engine is cold, step on throttle ONE time to 'set' choke . . . DO NOT START engine! Remove snorkel on top of carburetor and check condition of choke blade in primary (outer barrel). If closed (correct), push on lower edge of choke blade with your finger, it should have some spring tension.

If choke blade is open, adjust choke per manual.
 

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Opeler
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Just did a rebuild of my Solex. It still acts like yours at start, the choke doesn't seem to do anything in the warm weather and you need to sit in the drive for a couple minutes holding the RPMs at about 1500 or so and then it's fine.

Mine also did the reving bit. It ended up being a number of problems. Do you know if anyone has done any work on the carb in the past? Someone had on mine and they didn't put back all the pieces. Inside the vacuum housing for the secondary there is supposed to be a big spring. Mine had none. That caused some of the problem. The other problem was the linkage actually was loose. There is a nut with a ball on the end of it that connects the linkage to the carb. It is burried on the back side of the carb. Mine was so loose that the primary barrel part of the linkage would slip right off the secondary linkage and it would never force it closed again. The ball nut is tricky to get off. Search the Solex forum and you'll find a question I posted about how to get it off. I got good instructions from some folks on the forum.
 

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Choke cold start adjustment

Dan-MI said:
Just did a rebuild of my Solex. It still acts like yours at start, the choke doesn't seem to do anything in the warm weather and you need to sit in the drive for a couple minutes holding the RPMs at about 1500 or so and then it's fine.

Mine also did the reving bit. It ended up being a number of problems. Do you know if anyone has done any work on the carb in the past? Someone had on mine and they didn't put back all the pieces. Inside the vacuum housing for the secondary there is supposed to be a big spring. Mine had none. That caused some of the problem. The other problem was the linkage actually was loose. There is a nut with a ball on the end of it that connects the linkage to the carb. It is burried on the back side of the carb. Mine was so loose that the primary barrel part of the linkage would slip right off the secondary linkage and it would never force it closed again. The ball nut is tricky to get off. Search the Solex forum and you'll find a question I posted about how to get it off. I got good instructions from some folks on the forum.
If that's true, your choke is definitely NOT adjusted correctly!

With a 'cold' engine and correctly adjusted choke, you should only have to press the accelerator pedal twice to 'set' the choke, then be able to start the engine without any further drama and have it running at 'fast idle' speed all on its own, regardless of where you are or what season it is.
 

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hey, after pressing the accelerator once, i checked the choke and it was closed and resisted a bit when pressing down on it. so it appears to be fine, will try running it longer in driveway before leaving as noted. TTY later
 

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so i let it run for a while and i adjusted this screw that appears to be a 'stop' and the end of the linkage to raise the rpm from a near stall at around 500 to approx 700 where it ran relatively smoothly. After a couple minutes of idling the revs were near 1500 and so i backed off the stop screw till it was back to 900. Seems to have done well at traffic lights for an hour of city driving and slowly climbed at a couple of stops. After turning off at a store and upon starting the revs were very low again drove for a short while but i'm pretty sure that after a while it would climb again after a prolonged drive. By the way what I assume is the fuel mixture screw (with spring??) is set to 2 3/4 turns counterclockwise.
 

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edder said:
so i let it run for a while and i adjusted this screw that appears to be a 'stop' ant the end of the linkage to raise the rpm from a near stall at around 500 to approx 700 where it ran relatively smoothly. After a couple minutes of idling the revs were near 1500 and so i backed off the stop screw till it was back to 900. Seems to have done well at traffic lights for an hour of city driving and slowly climbed at a couple of stops. After turning off at a store and upon starting the revs were very low again drove for a short while but I'm pretty sure that after a while it would climb again after a prolonged drive. By the way what I assume is the fuel mixture screw (with spring??) is set to 2 3/4 turns counterclockwise.
The Solex does NOT follow normal convention when it comes to idle speed and mixture. The stop screw that in virtually EVERY other carb in the world is used to adjust idle speed is NOT used for that in the Solex. There are two embedded screws, one of which is the idle mixture (as you would expect) and the other is the idle air speed (which is how you set the idle speed). Do you have a Factory Service Manual to follow its instructions? Basically, the throttle plate setting is "fixed" by the throttle stop screw at a certain position, which is properly determined by an idle vacuum of 6 inches (allowable range is 1 to 8 inches, and you need to use a manometer to get this accurate a setting). THEN you set the idle speed and mixture by speed and CO in the exhaust.

That all said, I know that there is a way to do this with a bit less hysterics. I don't have a Solex anymore (like, for thirty years!) so I am a bit rusty on the correct procedure. You should look around this section and see what tips you can find. Or maybe Otto (the Solex expert) can chime in here?

HTH
 

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thanks keith, no, no hysterics here, lol. No, I have an 'owner's workshop manual' by Autobooks for opel , for me its somewhat helpfull ok so i think i know which screws your referring to and have been playing with one of them (in this book referred to as 'passage for idle air') I thought it was the mixture adjustment, what appears to be the idle mixture screw is closed. As far as proper adjustments, most of it is Greek to me. Will look around some more and check back to this post
 

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Discussion Starter · #13 ·
so after it warms up the idling seems to be fine for a while and thenthe engine revs up to 1500 and hovers there but seems to run smooth i have no tools to check compression etc thanx for the help so far tho
 

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just updating
i disassembled the thing and gonna need gaskets between the manifold plate and between the carb cover and carb. Turns out there's a tear in the diaphragm in accelerator pump. I think between the weak seals and the perforated diaphragm my probs may be solved, we'll see in the spring.
Funny thing is, is that the drawings in the owners shop manual I have don't exactly match the adjustment screws on my carb so i'll eventually post a picture of it when reassembled and maybe get some pointers then?
Happy Opeling, all yooz that live in year round 'summer'.
 

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Not sure if this is the right thread for this, but had been searching the threads for the last few days trying to figure out what was wrong with my 71 GT. Quite suddenly it started faltering at idle and would backfire terribly on the down shift and stall at a stop. My first guess was to check vac and timing. The vacs were good but my timing light was TU so I tried to do it "manually". No success. Then after my local parts place did not have a new dis cap n rotor, I decided I ought to at least look at mine, even though I had replaced just a few months ago. All looked well till I tried to turn the rotor and it rotated freely. I thought the nib must have broken, pulled it off and looked, and again, all looked fine. So I pushed it back down again and it stopped turning. I guess vibration had worked it up till it was merely turning via friction. Thought problem solved, re-checked 'manual' timing, but still backfire and stalls. Then I thought about how it was finally getting cool here in Florida and we had been getting alot of fog and dew at night. My tank was a bit low, so I bought some HEET and added gas... babied her around the block a few times and VOILA! No more stutter, stall or backfire. I had had this problem years ago with a 73 GT I had down here, but had failed to remember it. Does this problem happen up north as well, or is it indictative of some other problem with my tank. I usually try to never let the tank get below 1/2, but with the current probs at gas stations, I let it go longer than normal. Well, as I stated before, tis finally perfect driving weather in Florida, so off to take it for a lil spin.
 

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Discussion Starter · #16 ·
my carb pic

this is the picture of my carb I would like to make sure I at least know what these noted adjustments are and what they do before i fool around with em thanx in advance.
 

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Solex adjustables

edder said:
this is the picture of my carb I would like to make sure I at least know what these noted adjustments are and what they do before i fool around with em thanx in advance.
A - throttle lever choke link, "choke pull off" lever . . . NO adjustment
B - idle mixture adjustment . . . CW - leaner, CCW - richer
C - idle air (speed) adjustment . . . CW - less air, slower, CCW - more air, faster
D - primary idle jet, NO adjustment
 

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You can Tuna fish but you can't tuna solex

As we speak yet another manual secondary solex is winging it's way to Utah to be used on another car. In digging through several solexes I noticed a very interesting thing. Vacuum secondary carbs and manual secondary ones have slight jet changes. So yes given enough parts you can tuna solex.
 

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sounds fishy to me dave :D
 
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