Originally Posted by R72benz

I am confused. I have installed the Pertronix upgrade on my 4.5 M117, and adjusted the timing as recommended on this forum. Inspecting the plugs after 500 miles indicate it is still running rich......but much better than before timing adjust. I want to check the spark plug gap but can't find any info in my Owner's manual or on any of the tags on the car. I have the MB shop manual for the engine, put nothing on plug gap. I have searched the forum and read to gap the plugs anywhere from .028" to .045". My Bosch plugs came gapped at .031". What should it be?

Ron..aka confused.