I pulled the carbs off of my 1973 cb350f (which has been running great) to do a cleaning and inspection because one carb had a small consistent leak through the drain tube only when the bike sat. When I got the carbs off, I noticed these two small brass tubes sticking up in the center of the carbs. I attached a picture of them below. They are nestled under and on either side of a gas line in the picture. They had nothing attached to them before. To me they look like the should have vacuum lines attached. Also the bike has ran fine before I took the carbs off. Maybe they are something else? I’m just looking for answers.