Red,
There are some basic and easy techniques to adjust fuel/air mixture, then there are some very involved techniques. There are many posts regarding fuel mixture adjustments. Please search, you'll get quite an education. One tool mentioned is a gas analyser (can't recall the name). I guess there are very expensive professional ones (Thousands of dollars), and home use ones for about $100. Again, the search tool will yeild a wealth of info.
Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both tops
1994 E420