All the above _plus_ the venerable " B " series carby is _supposed_ to be damp at the air horn gasket , they were when new , the only way to stop it is to use Permatex # 1 on the gasket , a very bad idea indeed .
Better raise the float level to the spec.
Tight valves will also cause flat spots so check and adjust as needed , engine _hot_ , not warm .
