Yes, there is a gasket between the carburetor's mounting flange and the machined face of the cylinder, around the intake port. Make sure the gasket is not leaking (all four surfaces must be smooth: both sides of the gasket, the carburetor flange, and the cylinder's mounting surface). Ensure that the attaching screws are firm, too. I don't recommend putting gunk on the gasket, because it is so annoying having to replace it next time you take the carburetor off, when it delaminates and comes off with rough surfaces. If you want you can put gunk on one side only, so you only have one surface to clean in future.
