Z1OwnersClub GB

Please could someone advise me which way round the fuel tap rubber gasket goes in. It's the round one with 5 holes in. One side has a groove right around the outside and the other side is flat...ish. It's been a long time since I took it apart and I can't remember. Thanks in anticipation. Roger

I finally used my loaf and when I looked properly I could see faint marks were the original rubber gasket sat on the tap handle flat. The grooved side goes against the tap body face.

R