For 1973-80/1985-90 Johnson/Evinrude 1-cyl, 1.2-2 Hp | 2-cyl 4-6 Hp outboards.
Hub uses key
ID: 10.94 mm | OD: 38.4 mm
W: 17.8 mm | 6 blades

also crosses with:
Sierra: 18-3090
GLM: 89490
Mallory: 9-45210