Magneto Rx: - Bosch, American Bosch, and Robert Bosch - Robert Bosch - FF4 FU4 FF6 FR4 and friends

Guten tag! The F series appeared in the early 1930's or thereabouts. They were used as OEM by many engine builders and offered as options for others and for export. They are compact and very robust. They pack big wallop despite their small size. Here is some factory info to keep yours alive and well.