Hi all,
I'm asking for advise with slight desperation because I'm taking the 2CV to France next week.

I've looked at various postings on this site but can find no mention of this problem

When braking slightly harder than usual, the revs drop to the point when the engine dies. It re-starts straight away on the key.

The car starts fine, runs pretty well, apart from slight hesitation mid-range, light throttle.

When braking hard and this happens, it can be from a speed of 5mph or 20mph, doesn't seem to matter.

Carb's been off, I put gaskets on the spacer block (missing), cleaned the jets I can see, checked the float level.....is it something to do with petrol sloshing around in the carb.

This rev drop doesn't happen if I brake hard in reverse!

I've just about run out of obvious ideas!

Thanks in advance for any suggestions.

Thinking aloud here but…

Could you have an exposed wire in the low tension circuit that gets moved such that it earths under harder braking? My condenser barely clears the front cowling and I am amazed that never seems to short out (not a standard 2cv one in fairness). Loose wires on the back of the ignition or worn out bits inside moving around would be something I'd look for as part of this.

Dying HTs contacting something might potentially do much the same thing but I think they would have to be very far gone.

If that didn't work I'd be getting desperate but would try increasing the idle speed a tad (I have similar problems on a motorcycle where demanding too much of the alternator will cause it to die which can be got around with an excessively quick idle). In that instance asking for headlight, brake light, and an indicator will fairly reliably kill it, but I struggle to see how that would be the cause here.

"Cleaning jets you can see" - does this mean the visible ones ie secondary jet on left and emulsion tubes?
Main jet is not visible but can be cleaned without removing - that's in the the right hand chamber - and would be likely to cause the lumpy running if dirty. Make sure there is no crap in that chamber at all as this is the main source of fuel in normal running.
Have you checked idle jet on the front of the carb? This can often get blocked and causes erratic idle....

You may check/clean once more.

Getting a similar problem with a 425cc. Carb is a recent one from Roy.
It also slows down & dies after ticking over for a couple of minutes...

Hi Indian46,
Did this happen suddenly or did this start after you worked on your Solex carburator ?
In case you replaced the main gasket arrond the lid it could be you have a faulty paper gasket.
See the thread at the 2cv.nl forum @ http://forum.2cv.nl/viewtopic.php?t=109 ... ur+pakking
The picture at "Antons" reply tells the story although it is in Dutch.
Good luck. Walter

My motorcycle misbehaved in support of your carb this evening, cutting out as I indicated left to go back in front of the chap I had just overtook. Mercifully it came back when I cancelled the indicator.

Thanks for the suggestions.

I've taken out and cleaned the jets, (yet again!). Slight blockage in the lower jet in the left chamber. That's it I thought! No it wasn't, no change.

So, do I change the carb with one that's lying around: although if it is a carb problem I would like to solve it rather than simply replace it.

I have a Mehari electronic ignition: what symtoms would manifest themselves with a 'partial' failure?

I'm trying to think a little laterally!

Thanks again for your comments.

Try spraying WD40 or brake cleaner around the base of the carb and inlet mounts where it goes into cylinder heads to check you really havent got air leaks around the gaskets too....Do it whilst engine is running and revs will drop of you have a leak.

90% of carb problems are something else do the timing and tappets first before you start faffing sbout with the carb.
There is a way of setting the idle mixture on solex carbs and it sounds like the idle or slow running circuit in this case
Look in history for the VW tutorial for setting the almost identical carb.Ok its not the two choke progressive one fitted to our cars but the idle circuits the same