Mercury Mariner 4, 5 102CC Sail 1990 Outboard Service Shop Manual, Page 123Get this manual
3Place plate (a) over hub (b) of starter sheaveThen place spring housing (c) over starter sheave, inserting tabs (d) into pening (e) of sheave 5Place guide plate (a) over hub (b) of starter sheaveso that tab (c) of late catches inner hook (d) of rewind spring