These yoyos are stripped and need to be retapped. In addition their bearing seats all took some wear that have caused them vibe. I plan to try trimming down the bearing seats by about .01’’ each and see if that would make them smooth (and maybe later add shims to restore the gap width)
I also have a starburst yyj speeder that i need to hack a response groove in.
A retap should be enough to make it smooth actually. As the threading becomes worn down, it’s fairly normal for the yoyo to gain vibe. Message me if you need them repaired.
Retapping can fix the vibe issue like yoyospirit said, and he’s probably the best man for the job. I wouldn’t take too much off the bearing seats though, just clean up the edges with a light sanding so the bearings fit without sticking too much.
