The /2 BMW's are equiped with a magneto ignition. That is more or less a mixed blessing. More important is that it is very characteristic for these BMW's. The magneto is invented by Mr. Bosch, early in this century. Because it produced a reliable spark, independant from the battery, it was a godsend for the automotive industry, when batteries were still very unpredictable. They were used a lot before the war. After the war the battery ignition had taken over in most applications, because a magneto is an expensive solution when you also have a complete dynamo/battery circuit. But you could find them on tractors, militar machines, the big BMW and Zündapp motorcycles and racers. These latter categories because the spark from a magneto gets stronger with higher revs. The Bosch logo still shows an armature from a typical magneto of the early days.

There is alot to say about magnetos, so I have devided it in several chapters. To get a reasonable understanding of how a magneto operates, read the chapters:

When you are looking for more information, have a look at: