1 1/8 steerer according to the catalogue: https://www.retrobike.co.uk/gallery.../Marin+Catalogue+1992+v2/Scan10004-1.jpg.html.I have just bought this marin off ebay, I believe its a 1992 model, but I'm trying to figure out what the size the quill stem is so I can purchase a quill stem adapter before the bike arrives.
Any help would be much appreciated