I have a friend who is German. He offered this translation:
I am not sure if the description is really linked to the diagram. The x-axle of the diagram shows how much vacuum the vacuum-pump has to produce in relation to the distributor shaft speed. The vacuum adjusts the timing of the sparks for higher engine speed. The centrifugal weights are adjusting the timing of the sparks for lower engine speed.
The text describes how to check the engine speed limiter.
Here is the english translation:
1) Checking of the assembled engine speed limiter on the test bench EFZV 10: Adjust the spark-gap to 6 mm, raise the speed to 3200 rpm. (They mean here the speed of the distributor, which is half of the engine speed). No dropouts for the sparks are supposed to happen up to this speed.
2) Raise the speed of the distributor more. At 3400 rpm the first dropouts of the sparks have to happen. The dropout have to become more when you increase the distributor speed more.
Repeat the test while you decrease the distributor speed.
Here is the translation of the diagram:
The German word „Verteilerwellenverstellung“ means adjustment of the distributor-shaft.
„Verteilerwelle“ is the distributor-shaft
„Unterdruck“ is vacuum
U / min is rpm (consider that it is the speed of the distributor, then engine runs with double speed)
the distance of the contacts needs to be at least 0.4 mm
the dwell angle needs to be in the range of 59 to 65 degree (or 66-72% if the dwell tester shows %)
I do not know what the 3rd little picture under the diagram means
Hope the translation can save the problem.
BTW, the best dictionary that translates German/English in both directions is http://www.leo.org it is from the university in Munich and it’s free.