So a while back my DM2 went completely responsive (bearing did not even sound like it was spinning) I have switched it out and cleaned the bearing and the bearing seat, but no luck. However, I notices a small plastic piece sticking up in the seat. It was the same way on both sides. Is it possible my bearing is getting caught on this, causing the bearing to lock up?
It’s round and in the area where the should should be? That’s supposed to be there, it’s part of the injection molding process. You can safely remove it should you wish to.
I’d need more information.
How is the bearing lubed?
How did you clean the bearing? Did you clean the bearing properly?
Did you lube the bearing? If so, share details.
Are you using the wide bearing? I’m guessing you are.
Any other changes? Fresh string? What is the bearing being used?
sounds like something is happening in there. if you cleaned/swapped everything out, i would guess that yeah, its getting stuck on something. take it apart, put the bearing around the axle, snug into the seat and give it a flick. Is it free spinning or is it catching? I just took my DM2 apart and flicked it and it spun around 25 seconds before stopping, so I’m guessing thats around the normal. If its spinning funky or only for a very short amount of time, somethings gonna be wrong. try to eliminate one thing at a time.
I had my DM2 go a bit responsive and looked around the bearing seat, and saw the exact same piece of plastic you’re talking about. I also had the same thought, “Hmm… wonder if THIS is the culprit! This can’t be a good thing in a bearing seat!”
So I know where you’re coming from!
But it turns out that wasn’t it. As Studio42 mentions, it’s just an artifact of the molding process and isn’t likely to be the culprit.
In my case it still turned out to just be the bearing. I had another bearing that I knew for sure was perfectly unresponsive, swapped it in, and the DM2 became perfectly unresponsive. I think I just left that bearing in there, so I don’t think I have any better advice. 
I run my bearings dry since they are all ceramics, I use pure acetone, dry, paper slip, then another acetone bath with fresh acetone, spin dry.
It’s too damn clean, man! Too clean!
Just kidding.
But seriously, despite (or because of? I don’t know) fast evaporation, acetone can still leave a film. Now, I doubt that’s the culprit. More like an aside.
But seriously… I’m suspicious of bearings that are that extremely clean and dry. For no good scientific reason. None at all. In my illogical feeling about this, I would always want even just a tiny bit of lube or DryPlay in there. But in complete and humble honesty, I have no good reason for that.
That shouldn’t be an issue, I usually clean my bearings once a week
Ya gots to read the finer points…
But surely it isn’t that, because I use that same bearing in my other yoyos and they preform flawless
You shouldn’t need to clean them that often. Not even once a month. Once you get them completely cleaned out and then do some maintenance lubrication, you’re set. If you need to add lube once in a while, then no big deal.
If you take that same bearing out right now, and plunk it into another yoyo, you can play for 10 minutes or so without any performance issues?
Could be the seat, after all. Make sure it’s extry-clean (but don’t use any plastic-dissolving solvents to do so!! Just use water and a lint/debris-free cloth of some sort).
I don’t think it’s that little plastic piece, though; it’s probably found in all DM2 yoyos, if mine and Studio42’s are any indication. And in my case, it was definitely not the cause of responsiveness.
I clean them out because I use them a lot in a really dirty environment so they seem to slow down. And yes, I could. Infact I have it in it right now.