Hi
i have a 1.4 with usual dodgy running issues it idles eratically and seems to over rev and sometimes overruns.

I noticed when i took the air filter cover off that only one chamber on the carb has a flap, it looks as if there should be a flap in the other chamber. Am i right in thinking there should be a flap in each chamber? Could this be the cause of some of my running probs?

early carbs (weber 83) had a twin carb flap, it's the choke actually.

later on, they realised that a choke valve on the 2nd barrel is a bit of dead weight, since normal people don't floor it with a cold engine, the 2nd valve got eliminated. the rod that holds the flaps hasn't changed.

your running problems seem like a dead floaterchamber gasket.

you could still try if the 5 bolts of the floaterchamber cover run loose by removing the air filter housing + gasket and tighten them.