@haroon47
Brother i myself am another victim of Insane Fuel Consumption by Carby Cultus.
I have tried all those things you mentioned in post#1. What road side mechanics do to adjust the mix is start the car, let it idle. Then start tightening the mixture screw right before the point where car starts to choke itself to stall. At this point they start observing exhaust gas with oscillations in it (Same as when you idle a CD 70 and put your hand on the exhaust, you can clearly feel the stroke by stroke exhaust burst)
Now they start increasing the mix until the stroke-to-stroke exhaust burst vanishes away and the exhaust starts coming out in one single stream.
I know its kinda lame way to explain this whole scenario but that is how they do it. I have some serious doubt about this method and its accuracy.
The best way is to get the mix check via an emission analyser present with those enercon guys. They check emissions in idle and then rev to about 3500 rpm and check again. But as my experience with one of them, he said its fine (all you need to do is either perform a carb service or use 2 carb cleaner additives in 2 complete fills of petrol, consume it to its dregs and then refill again. And then again come for a scan.
I did use one bottle of additive but the response was pretty much the same. A jerk on every throttle increase under load. So i left the problem as is at that moment.
So if you do find a way to fix it up, by locating the actual cause, please do share as it would help alot.