http://i448.photobucket.com/albums/qq201/Neo50/003-1.jpg
Here is a pic of the bottom of the cleaner on my W-1 off my '50 3100. The shaft height is 1 1/16" and there are no indentations. Hope this helps.
Sounds like your carb is flooding because the needle isn't seating allowing fuel to keep flowing. Adjusting the float level won't help. You won't be able to tune the carb until the fuel level is correct.
Scott