I have a 20HP engine that lives in salt water. Last fall I noticed that the pee hole was dribbling more then its normal flow. I reading the manual I saw that there was a flush port on the side of the engine that I thought I'd use. While turning the screw the whole assembly just crumbled away (see picure). Long story short I'm trying to find the replacement assembly for that port, or find out if I can just bypass it. In searching the Honda parts site I can't find the replacement part. Any ideas on what it is called?, or if I can replace it any how to suggestions?

Thanks in advance.