Today a guy came to me in desperation, he had been trying to stop his carb flooding for days.
I removed the float only to find that where the needle rode, the tang was deeply pitted from wear.
Every time the float got to the top of its travel, the pit would cause the needle to be forced sideways, making it leak
I gripped a wrench in the vice and placed the tang over it.
With a fine punch and a small hammer I tapped the tang on the reverse side of the pit until an indentation was made, forcing material into the pit. from the backside.
It would have been good to have had someone to hold the float..
I then turned the float over, and used a very fine 4 square file to clean up the tang.
Refitted the float and hey presto, no flooding.