Hello everyone,

I recently dropped a reman motor in my gen 1 and I'm having some trouble getting it set up right. I know the manual says 7 degrees BTDC for basic ignition timing but I am not sure how the vacuum advance figures into that. Right now I have it set at 7 but when I bring in the vacuum advance (I plug it into the manifold) it adds a ton of timing and scares me so I just have it unplugged. This is my first project so all this is very new to me. My questions are:

1. What should the timing be with the vacuum advance

2. What should the timing be without the vacuum advance

3. Where should I connect the vacuum advance hookup (I'm running a Weber 32/36, all emissions stuff has been deleted)

Thank you so much, and I've also attached some pictures of the build.

Set the timing to 7ish with no Vac. I tend to always run more than that but let your engine tell you what it wants once you are driving it.
The factory carb, the Dist vac port is at a position such it does not receive the vac signal till the throttle is opening.

The way this works there is little advance at idle, essentially what the mechanical amount you have set it at.
At a light throttle cruise there is allot of vac to the dizzy offering allot of advance, this is to provide torque and a complete burn cycle for economy.

As you open the throttle more the vacuum diminishes under load, this reduces the advance under high power when the cylinder pressures are high with a dense fuel charge which ignites easier. This reduction in timing reduces the chance for detonation/knock.

With the carb you have, either the throttle plate is open too much at idle or the port is cot controlled by the plate.

Were I would start, connect the vac line, start engine and readjust the idle speed presuming it has increased with the vac advance.

In the past I/we used to need to chamfer or drill the throttle plate to get it where it needs to be for proper control of idle ports etc.

I have no experience with the new China carbs for what they need to run right. I expect these horror stories is simply because carburetor tuning is a lost art.

Thanks for helping to clear that up. I'll set it to 7 and run the vacuum canister to ported vacuum instead of manifold. My Weber is a genuine European made unit, but I've still had a hell of a time setting it up. It used to run lean on the top end but I fixed that by upping the jets and the float height but now its running really rich at idle.

Nice that you have the real thing, there are quiet a few steps and needed brass to make them right, Do you have a wideband meter in the system?

Part of getting the idle system right is determining if the throttle plate is covering over the idle ports such that thy start to get uncovered only as you are oping the throttle.
If the throttle plate is open and a progression port is open it will feed fuel before it is supposed to.

With the carb you have, is the primary the outer or inner throat?

Yes I do have a wide band O2 meter. It idles currently around 10.7 to 11.5 despite having the idle mixture set for max rpm using a digital tachometer. I know the Weber instructions say not to turn the idle speed screw more than 1.5 turns, but It idles so poorly and shakes pretty bad unless I turn up the idle speed, which is probably exposing the idle ports like you are saying. I have the 32/36 DGEV, I believe the primary throat is facing outside the engine bay towards the driver side fender. Currently I'm running a 65 main idle, 55 secondary idle, 45 main primary, 50 main secondary and everything else I left alone. Also I had to increase the float height and switch to an electric pump because it was running out of gas quickly running down the highway at 3500 rpm.

If the idle speed with the T plate in the proper position over the ports dos not allow enough air. drill holes in the plate to allow additional airflow. Start small but I tend to find a need for a few 1/16 or a bit larger holes. These can be soldered back over if needed.
This will offer a better off idle "tip in"

To test where you are at use a slow opening from closed throttle and listen as much as other senses, I find I have my eyes closed during this phase. When I was learning this stuff was well before widebands which obviously are a superb tool. Hesitations as well as sound changes can guide you to mixture changes in the port transition. A tiny opening of the throttle should be a tiny rpm rise, if the ports are not opening as they should you can detect a non linear rev change and exhaust note. The wideband should backup what your ear hears, very slow opening of idle should have no mixture swing. If the mixture drops or rises with a slight slow tip in the ports are not opening at the correct time.
Till the idle ports are opening when they need to the engine will drive like poo and not respond to reason with jetting. Once you get this transition off idle setup then you go to tuning the size of the idle and main jets,
On the 2.6 with factory manifold you will never get even mixture in all 4 cylinders, not possible. The single carb/ injection is what gives this motor the bad name and low power. Center cylinders run rich, outers are lean, and not even on each end. #1 is leaner than #4. This sucks but it is what we were given.

We did ultimately in the mid-late 70s get sniffers that we stuck a probe up the tailpipe, accuracy was marginal, we stuck to reading plugs, probably a lost art. I think I have lost the art at least. Mind you we had lead in the gas which colored things fast.

FWIW, in recent years I converted to factory dual downdraft carbs on my '72 Colt, the 1600 baby brother to the 2.6. Allot more low end torque than the single carb. After a waterpump failure which I did not recognize till way to late I swapped to an engine that had a shaved block as in the tops of the pistons were cut too, This is along with a well ported and cut head.
Working with the wideband and discovering these Asian market Solexes have 4 stages of idle adjustments, this little car makes so much low end power that I rarely rev over 2500 till you need more in 5th just for road speed, our highways here many times one cruises at 80 which is 4K revs and this car now averages 42 mpg, they only got 26-28 when new. This is all in porting, raised compression and extensive time getting the carbs setup. Waiting for the state to stop spreading the sea water on the roads so I can get back to driving my car.

Very interesting and helpful information, thank you. It explains a lot of the issues I have been experiencing. I've been going nuts trying to fix the problem with just changing the jets. My Weber hesitates when I give it throttle rapidly, and my mixture reading on my wide band rarely stays consistent. I knew I had the T plate too far open but I couldn't get it to run well any other way. Even then it vibrated pretty bad at idle and I still had the balance shafts in my motor. It wouldn't idle smooth below ~1000 rpm. Could it be possible I need to adjust my secondary throttle plate further open before I begin drilling out the primary? I never knew it would take so much effort to set up this carb, I naively thought It would be ready to go out of the box.

Good to know the cylinders don't get even mixture, when trying to read the spark plugs I was always confused with their inconsistency. Makes sense now.

The mileage and performance you are getting with that multi carb setup is very impressive, makes me want to get one some day when I have more money. Your 72 Colt sounds like an awesome ride. Too bad they still use salt on the roads up there instead of something less corrosive, part of me thinks its just to get people to keep buying new cars...

Oh I wish I was in Ohio where they use fruit juice to deice the roads I do not recall if it was date or plum juice. I hate working on our vehicles since they are heavily coated with chainsaw bar oil now.
Yes to adjusting the secondary plate or drilling it. Check if the secondary has idle progression ports as well, some do.

I loved my 2.6 with dual Webers, power everywhere from idle to 7500. Lovely engine, it is up in Canada now. These engines are superb when they are not trying to suck through a straw.

I wish a dual carburetor setup was in my budget, IÔÇÖve just about lost my patience with the single carb. I ended up drilling about 6 1/16ÔÇØ holes, got the thing to idle without exposing the transition ports but I had to turn out the mixture screw more than 2 full turns and it still ran on the rich side and rather rough. I was wondering what values I should be reading on my wide band at idle, currently IÔÇÖm around 12.5 to 13. The engine does run smoother and I feel like I have more power but IÔÇÖm getting horrible gas mileage, about 7 mpg. IÔÇÖm thinking about switching to one of the older milkuni solex mechanical carbs that came on the earlier monteros.

The early carb is fine when they are right. At least they can be made to be right, the later electronic carb, when they are wrong there is no telling how to make it right.
I have been chasing issues with my early carb but it seems to be down to choke adjustments, to slow to open, and I think I got water in the gas, can not blame these on the vehicle. We got warm here today and I went up in the field and put a wrench on the crank of my turbo Monti, That might be my easiest fix to swap it over.
7 MPG is way low.