HATZ series 1D speed regulator spring 04052900 Item description:
Producer - German company HATZ.
Catalog number: 04052900
Item no. 18 from the catalog card (second photo)
Spring for RPM range: 1501-1800
Winding wire diameter 1.7 mm Application: HATZ engines 1D30 1D40 1D41 1D42 1D50 1D60 1D81 1D90
Original spring, brand new.