Spring clutch system 139 FMB-B and 139 FMB Masai, Orion, Mash, Archive... 50 New adaptable clutch rod spring for motorcycle 50cc Mash Fifty, Masai, Archive, Motrac... with a vertical 139FMBB 50 4T or horizontal 139FMB 50 4T motor. Technical characteristics and dimensions Brand: adapatble Material: steel