Can somebody tell me what the stuff is on the left side of the carb. It has a cover with a P : on it and a gasket. What is the purpose of this stuff. I took it apart before when cleaning carb but didn't know what it was so I put it back together the way it came out I hope.

 

do you know what I'm talking about, it's hard for me to explain when I have absolutely no idea what it is or for. It is on the opposite side of the throttle cable lever.