[5valve]

I'm waiting for used first gen. 250f kick to fly in.
It should then look like this.

If new type kick from 2012 and on bikes is applicable to your bike, then you might have worn spline issues, as all this stuff is interchangeable.

On the other hand, my original kick boss had excessive play in the splines, which I eliminated fully with green loctite.

Maybe there is loctite residue on your splines.