Hi Iris. Was this ever resolved. I have the same faucet and the same problem and can find nothing anywhere about it.

Hi Mwk and welcome to The Plumbing Page at ANHD.com. You're responding to a 5 year old dead threads so I gave you one of your own. Please check the date before you post.
Thanks
Since all plumbing problem's aren't exactly the same would you post your complaint in detail so we can address it. Thanks, Tom

Hi. Sorry for replying to an old post. It was literally the only thing anywhere I could find on the problem I have. I have the same moen faucet as the one in the post. It has no threads for an aerator. Just a plastic black piece with a single thread-like ridge. I tried removing it with needle nose pliers as suggested in the old post, but it will not move and seems to be part of a moulded plastic underside to the tap. Wanted to know if this is fixable, and how or if I need a new faucet. Thanks so much.

I think it is an old Moen 7650.

It has no threads for an aerator. Have you checked the inside of the spout for inside threads? Back to you, Tom

Have you checked the inside of the spout for inside threads? Back to you, Tom

Thanks Tom. Yeah checked inside. It's just a smooth conical ridge.