I consulted six books on air-cooled engine rebuilding, and similar topics, plus the Porsche Service Manual, and none of them described what this switch is supposed to do. Except for the Porsche manual, none of the books even mentioned it.
The Porsche book told how to adjust it, but what is it for?
It is adjacent to the throttle linkage and is near the back of the engine; part of the linkage actuates the switch on this box's top. Sorry the photo does not show the actual switch mechanism on the box top.
