Hey Everyone. I was installing a jet kit on my 07 S model and when I took the top of the carb assembly off I noticed that there was no tiny o-ring on the side (the one they tell you not to loose). No outline marks on the cover so I do not think there was ever one there, and looking at it I would have no idea why one is needed. Did they do away with these in the later models and if not how important are they? Thanks!