solex carb/adjustments?

[edder]

hi guys first time poster long time reader.
I've read another's post regarding adjustsments 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 to low to the point of stalling. After driving a short while after downshifting and coming to a stop (at a light lets say) the car is reving incredibly high. I dont know how much more info you need but does this sound familiar?

[weatherman]

Does that sound like a vaccum problem to anyone else? Had that happen to a buddys, and his intakes where loose and caused a vaccum leak.

[edder]

ty i'll check that out as best i can and let ya know

[edder]

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 cuz someone years ago sed 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 theres no leak there because it did give a little (if i understood the post correctly!) I'm tryin to make heads or tails out of the drawings and stuff regarding the carburator and to tell the truth I couldnt 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 carburator help??

[tekenaar]

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.

[Dan-MI]

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.

[tekenaar]

Originally Posted by Dan-MI 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.

[edder]

thanx guys I'll post back tomorrow afternoon!

[edder]

heya after pressing the accelorator one i checked the choke and it was closed and resisted a bit when pressing down on it so it appears to be finewill try running it longer in driveway before leaving as noted. TTY lata

[edder]

so i let it run for a while and i adjusted thuis screw that appears to be a 'stop' ant the end of the linkeage to raise the rpm from a near stall at around 500 to aprox 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 itwas 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.

[kwilford]

Originally Posted by edder 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

[edder]

thanks kieth no no hysterics here lol. No I have an 'owners workshop manual' by Autobooks for opel , for me its somewhat helpfull ok so i think i know which screws your refering to and have been playing with one of them (in this book referred to as 'passage for idle air) I thought it was yhe 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 somemore and check back to this post

[edder]

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

[edder]

just updating
i disassembled the thing and gonna need gaskets between the manifold plate and between the carb cover and carb, Turns out theres a tear in the diaphram in accelerator pump. I think between the weak seals and the perforated diaphram my probs may be solvrd, we'll see in the spring.
Funny thing is, is that the drawings in the owners shop manual I have dont exactly match the ajustment screws on my carb so i'll eventually post a picture of it when reassembled and maybe get some pointers then?
Happy Opelling all yooz that live in year round summer.

[wrangler]

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.

[edder]

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.

[tekenaar]

Originally Posted by edder 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

[nobody]

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.

[baz]

sounds fishy to me dave

[edder]

thanx fellas you guys rock

[gr_diver]

Concerning what you have marked as A, there is an adjustment, as it controls the fast idle speed.
With engine fully warmed up (!important!), remove the air-cleaner housing, open the throttle (by hand) until you can push the choke flap completely closed, keep the choke flap there and then release the throttle (you have to do this a bit quick or the engine might stall during having the flap closed, or you can just shut the engine, do it and then restart without pressing the accelerator pedal). The choke flap should return to the vertical position BUT your engine will be now running on fast idle, which should be about 3200-3300 rpm. If not within this, you need to adjust the position of the lever on the threaded rod, by loosening the two nuts.
To increase fast idle speed loosen the top nut and tighten the bottom.
To reduce fast idle speed loosen the lower and tighten the top nut.


P.S. In order for the fast idle mechanism to operate correctly, you should make sure that inside the choke housing, when the choke flap is closed, the throttle actuating spindle rests in the middle of the top step of the stepped cam (see left pic). If not you should only slightly bent the little tab on the choke valve's spindle that touches the side of the stepped cam plate accordingly to achieve correct adjustment (see right pic, tab in red circle)...

[Crazy Harry]

I rebuilt my Solex recently. The job went reasonably well. I used the recommended starting settings for the idle mixture screw and the idle air adjustment and the engine fired up easily but idled way to high. Upon fine tuning the idle speed the engine ran rough when getting near the operating range, just like before the rebuild. So I backed out the mixture screw and air adjustment again. Now the engine starts with great difficulty, must crank for a long time but eventually it starts and runs too fast and unevenly ! Any suggestions . I really want to give the Solex another chance before I bite the Weber bullet.

A few more things I noted that might help with the diagnosis:
1. Before the rebuild and after there is an intermittant drip of fuel into the primary venturi hence rough idle and rough operation at constant speed,
2. The leaf spring that pushes down on the float hinge was missing,
3. The idle jet screw was overtighted in the past so the head is galled and the holes on the barrel are deformed (see attached photos). I know this is not adjustable, but someone before me must have thought so!

I'm sure these these are contributing to my problems. Any Solex suggestions would be welcome. Where can I get a replacement idle jet (g47.5)? Do I need the leaf spring for the float, if so where can I get one? Is there a default starting point for setting the throttle stop screw? I realize this isn't adjusted until the basic idle is achieved and the choke is set, but considering that someone tried to adjust the idle air jet has the trottle stop screw been misadjusted as well? One other question: There is no vacuum diaphragm on the secondary, the secondary is mechanically actuated from the throttle linkage, is this the correct configuration? The GT is a 1971 model with a 19S engine and a manual transmission. The carb tag number is 3441549.

Thanks,

Harold.

[opelbits]

Harold-

I don't exactly have answers for you, but I do have the Opel Solex training and repair/service modification manuals on cd.
They are a wealth of information.
Send me your address in a pm and I will send you a copy.

Plus, I have many Solex carbs for parts. If there is anything you need, I can see if I have it.

[tomking]

I am not the expert, but I believe all GTs came with mechanical secondary rather than vacuum secondary. I dont think that screwdriver slot deformation is your problem. Search this forum and you will find lots of problems and answers and likely yours also.

[BQS4]

I have several jun...ahhh, used solex carbs, I can yank a few pieces off if you want.