Got the jet from Ken today, I'll try it in the evening. He even included a special tool to put this tiny jet in place. Mind you, it looks just like an ordinary toothpick! Thanks, Ken!

Didn't fix my top speed, but acceleration has definitely improved. I'm bothered by the top speed only because I know it should be able to reach more, but 70-75 kph is the perfect cruising speed for me in the 2CV.
My engine is a A06/664 which originally had 7.9:1 compression. I read somewhere that it might have had a different camshaft? Can anyone confirm or deny this?
High revs are not the problem. I can easily reach over 80 kph in 3rd gear, if I waited a bit longer maybe I'd get to 90. I also changed plug gaps to 0,5 mm to see if it helped with a possibly weaker spark, but there was no change at all. It does not stutter, jerk or do anything weird, just won't go over 100 kph in 4th.

What gear box are you running? 2cv4 maybe?

I found the easiest way to get the jet in was to use a dentistry tool

Thought I'd resurrect this thread about jets. I had the spark plugs replaced on the 2CV last week, the plugs seemed fine but had been working 'a bit hot', I'm looking to use the car to go to Orkney in two weeks time and I'd really like to get this 'running a bit hot' issue sorted. I'm guessing (correct spelling, Mr. Wallace ) that the carb is running weak so needs a bigger jet, I assume the 107 size is the jet of choice. Is this a job I can do, and what do I need as regards tools, etc? Cheers.

If you definitely know it's running a bit hot and that a bigger jet will solve your problem ... you'll need a 12 mm spanner and a small flat bladed screwdriver for the actual job of replacing the jet. You'll also need to remove the top of the carb so you can see what you're doing. It's late and I've been drinking marmalade vodka (of all things), but:

1. Remove the top of the carb by undoing the six slotted screws. Lift the top off being careful not to disturb the floats as you do so. You should be able to leave the fuel pipe and the choke and throttle cables connected but you might find it easier to disconnect them so you can put the top right out of the way.

2. On the side of the carb, low down just behind where the throttle cable hooks on, you'll see a 12mm bolt head. Undo and remove this, being careful not to lose the copper sealing washer. Unless you've drained the fuel with a bit of rag or a siphon or whatever, it'll all drain out of this hole ... you have been warned! Poke your screwdriver in the 'ole once the fuel is drained and you'll see a smaller hole inside the choke. This contains the main jet. Undo the jet, wiggle it about until it comes out of its hole, then remove it.

3. Personally, I've never found it necessary to use a toothpick or anything else to hold the jet while I insert it. Put it into the choke with your fingers, then fiddle around with it on the end of the screwdriver until you catch the thread. It's easier to do than to describe. Carefully screw it in, then reassemble the carb.

4. If you really want to go to town, you can get a complete rebuild kit from Uncle Roy with a 107 jet included, then you can completely strip the carb, blow through all the passages with compressed air and replace all the gaskets. If you do this, have a look on the front wall of the front choke and you'll see three small holes at the level of the butterfly valve. These are called transition holes and their purpose is to provide a dollop of fuel when you push the throttle down from idle; essentially, they supply fuel between the idle circuit shutting off and the throttle butterfly opening. If they're blocked, the car will hesitate or even stall when the throttle is blipped. Blow them through with compressed air while the carb is in bits.

Apologies if I've told you stuff you already know! If you're struggling with any of it, or need the loan of a compressor, I'm only up the road and you're welcome to drop by for help.

One of your brakes are dragging (maybe master cylinder) Check it out....

RT,
very good instructions, despite the marmalade and vodka...

A few comments. though?
I've been changing jets on Solex carbs for longer than I care to remember and a wooden toothpick/cocktail stick turned out to be the most effective piece of kit that's ever fallen to hand, not just for removing those 'grub screw' jets, but also for refitting the little blighters.

Also, the transition drillings do not provide extra fuel when the throttle is opened quickly, as that is taken care of by the accelerator pump.
What they do is allow the idle circuit to supply mixture into the carburettor throat when the butterfly is opened slowly and the vacuum, which existed below it when it was closed, begins to act on the volume of air above the butterfly.
Since it's still not far enough open for fuel to be drawn through the main jet, those transition drillings do just as it says on the tin.
That is to supply mixture via the idle circuit during transition from idle to main jet, with maximum delivery limited by the size of the idle jet and the air bleed which feeds it.

ken

Thanks for the replies guys, think I'll look into getting something done.

Isn't that what I said?