560 Fuel Mixture Adjustment
 

Hi all

In looking at the slightly sooty look of the plugs on my 560sl
I'm thinking it may be running a little too rich. Fuel economy seems to be getting worse too.
My question of the day is re that adjustment (allan key type screw) in the top of the fuel distributor.
I understand that turning in one direction will weaken the mixture, the other will make it richer. What I don't know is, which direction to turn it to do either. Also does this adjustment only effect mixture 'at idle' or 'accross the board' ?
I also think I heard somewhere that this adjustment is quite sensative and any changes made are not reflected right away. I was told the 'computer' takes a few miles of driving to compensate.

Also, can this adjustment be done without the use of special testing equipment?
The car reciently passed emission tests and doesn't blow black smoke or anything and run's seemingly well. Just want to get the best performance possible.

Thanks in advance for your help guys.

Barrie