I just went out and looked at my 81 "K" model to see of it had an o-ring or a gasket. I took the screw out and did not see an o-ring or a gasket of any sort. What I saw was a tapered needle that when removed allowed the gas to run out of the hose attached to the bottom of the carb float bowl. I hope that helps. If you need me to look at anything else for comparison just ask. Also, I think the fiche indicates that #1 is a gasket kit for the float bowl.