Quick update - after the carb re-tune, the car ran perfect for about a week - until we took it on a 200 km Autobahn blast. The heat warped the carb's lid once again and everything went to shit. Using some glue to fix the carb lid screws solved that - or so we hoped.
Running behind
@_Jules_ on the way to ringmeet I saw the car blowing smoke whenever she accellerated and sure enough, when we got off the Autobahn, Karl refused to idle, even dying when slowing down for turns. I fiddled with the carb, a garage fiddled with the carb, cause after all the carb trouble, what else could it be?
Until
@nicjasno checked the spark plugs, which all were fouled from too rich mixture. So we got a new set of plugs and I re-tuned the carb by ear on the Ringmeet campsite. After trouble-free jorney to Berlin we hooked the car up to an exaust meter and tuned it properly - but it still ran like shit.
So, we re-checked valve clearances and, lo and behold, the outlet valves all were too tight. Fixing that made Karl run smooth as silk for the first time since
@_Jules_ bought him.
Oh, and we also had to replace the wiper motor before ringmeet, but that was very straightforward.
And in the next episode - we convert to a manual gearbox using a donor car from Finland (hopefully!).
EDIT: I just realized we did not report that
@_Jules_ rebuild the carb herself and we re-tuned it properly first.