Went for a little trundle out this morning,not in my A7 but the Bayliss Thomas.Set off late morning (10.45am) and travelled a few miles quite happily. Then the engine started to missfire/cough/splutter and behave in an very naughty manner indeed. I pulled up for a quick inspection under the bonnet to soon realise the problem being an ICED CARB'
Now you might think that I live in Lerwick but no I live in sunny Suffolk!! Am I the first to experience this common problem this Autumn? The ice had formed over my Zenith carb beautifully.

Oh. I knew it would come to this.

I put it down to global warming! or is it cooling?

Any fliers on the forum will know that carb icing can occur in a variety of conditions and can have fatal consequences should it happen at low level. The previous rough running you experienced is a warning sign to select heat to the carb and cross fingers that it will do the trick before the engine starves. If it were particularly troublesome, I suppose you could follow aviation practice and route a pipe to carry warm air towards the intake (from the exhaust manifold area) with a bowden-cable operated flap to close it off when not required. At least, on the ground, the consequences are less likely to be serious.

Wonder if it may help by wrapping an old sock around the carb'

Well I never!. Although I have often experienced it in aeroplanes with piston engines with updraught carbs, eg Lycoming, Continental etc, I have never heard of it in a car before. Piston aircraft have a special arrangement whereby heat can be selected by a lever in the cockpit which directs air in to the carb that has been warmed by the exhaust, melting the ice which passes through the engine as moisture.

Ideal conditions are ambient temperatures between about -10c to +20c and when humidity is high.

There is a legend that the mini originally had the engine the other way around , with the carb at the front, BUT it iced up! They then made them all the other way around so that the distributor got wet instead!

Steve

My Bayliss Thomas (now for sale[:))has the carb on the opposite side to the manifold/exhaust. How sensible I thought compared to my A7 which is sited, well we all know where. Now with some cold weather driving of both I can understand Mr Austins practicallity