Its hard to tell from the photo but the fork that engages the pin on the diaphragm looks to be high. In most cases the fork is usually even with and parallel to the flat surface of the surrounding carb body. If the carb is flooding, the needle is not sealing properly or its pop off pressure is set too low. Either problem could be caused by a defect, damage or improper adjustment.

I'm not recommending this but some people have actually removed the part of the pin on the diaphragm that engages the fork as they feel it serves no purpose. This comes from some very knowledgeable people and you can find reference to this if you do a few searches here on RCU.