If the linkage needs replaced that is one thing. If you have excessive play in the throutle shaft then you may have a vacuum leak.
The seaping gasket is evidence that the float is set just a little too high. Gas shouldn't "rest" on the gasket. It should rest below the gasket just slightly or any gasket on any carb will seap. They aren't "liquid tight". Just resistent to sloshing and keeping gunk out.
