No on both counts I'm afraid. I'm actually looking to come down on the 23rd November for 7 days and I'll be relaxing on the motorway in the C4 with the cruise control on.

A few years ago, one typical December evening, I was driving a non-2cv and it started running badly, I can't remember exactly what I would have said was wrong with it, but it was generally coughing and spluttering. Over a period of about 10mins it progressively got worse until I thought it best to pull over before it died somewhere inconvenient. I spent the next 5mins wondering what was wrong with it and wishing I had breakdown cover, I was many miles from home. After which, at a loss for any other idea, I tried restarting it, it fired straight up and ran fine. I can only assume that was carb icing and the 5mins break was enough for the engine warmth to thaw it out. It never did it again.

Absolutely right, Joolz. By switching the engine off the engine temp actually rises of course as there's no cooling effect which allows the frozen water condensate to melt and vapourise so after even only a minute or so, everything's fine. So annoying. In the early 90's this was a very common problem on motorcycles, most of which had carburettors rather than fuel injection, as did many cars. The fuel companies denied it existed UNTIL cars started suffering. Sadly, all this manifested itself just as the emmision regs forced car, and bike. manufacturers down the fuel injection route (nothing wrong with that) and it was all quietly forgotten about, unless you drive/ride a carburetted vehicle of course!

Ken, choke is fine thanks and starts when cold perfectly, winter or summer.

I know the icing is going to happen down to the last yard of my first mile to work, despite warming the engine up longer than usual, so I just live with it.

Yes, I've fitted a 5% larger main jet, but this has no bearing on choke operation does it.

Your .pdf doc explains this wonderfully, thanks for the link.

After being caught out yesterday by a heavy shower that soaked the seats as the hood was left open during a trip to the shop, I've now got the 2CV sat outside in the sun to dry. It's a nice, sunny morning.

I had carb icing last February ,2 stroke aircooled and carburettor fed Vespa. Mate and i were riding back from the Dragon rally in Wales ,him on a Lambretta, at about the same moment at a high point on the A5 after Hinckley still 90 miles from home when it started snowing and getting dark we both started to lose power and splutter ,had to pull into a truck stop and let them defrost .

Carb icing, or 'glacé sans plomb' is a soft, sugary, edible layer that forms I've the mouth of the carburettor under very specific circumstances. As previously mentioned it can cure itself when the engine is stopped because this can allow the water which builds up in the air filter to dribble down and dissolve it, causing the icing to dissolve in a puddle under the car. You can also prevent it from happening in the first place by using a special mixture in the fuel when the weather is cold which will cause the formation of completely harmless 'carb marzipan' instead.

Over in America you get carb "Frosting"?

Daimlers and the like get the softer Royal variety ( with addition of Glycerin to the mix)

there are a "100s of 1000s" variations.

cold ( not necessarily freezing) and really high humidity - foggy misty drizzly weather

the drop in pressure in the carb and the cooling effect of the evaporating fuel causes the atmospheric moisture to condense out and freeze on the jets of the carb.

Ive watched it happen on a Solex carb in a VW T25 van ( where you could sit in the back and watch what was happening in the engine bay as someone else drove it around) a dirty little snowball formed on the jet. Cant say for definite if it happens on the 2cv as its difficult to do that trick, it definitely feels like it but the long inlet tract on the boxer engines dont work well when the engine is cold but not necessarily due to ice forming in the carb

I've often thought this too. On a v cold morning with those long inlet tracts already close to freezing, even colder fuel/air (and in this case, frozen water droplets!) probably has a mild supercooling effect thus making things even worse.

I used to get all this with my S2a Landrover a until I sold it a few years ago. I remember one dreadfully cold and humid morning I opened the bonnet to investigate after only a mile into my journey and the carb was completely covered with frozen condensation. Lord knows what it must have been inside. As usual, a short 'rest' restored things to normal.