Is rubber plug needed

I was reviewing the manually and notice the missing plug upon opening the carburetor. the plastic baffle was missing too. This isn't my rancher. Friend has owned it for 6 years but it hasn't run for the last two. Seeing it sitting in his garage I volunteer to work on it. It has serveral problems and we're knocking them down one by one. Knowing the carb needed some TLC and prepared to open and clean the inside then finding parts missing gets me to wondering if they were needed. Since I assume the bike did run fine before. The pic does represent the rubber plug I'm referring too. I did get the baffle in a kit but not the plug. Thanks again