Doesn't need to be a clone to do that, a Singer 15 will also.
I had one machine that was really stiff for the stitch length lever, so hubby took the cover off and there was a a spring steel type piece somewhere in that area. He flipped it around, and put it back together. I had a really smooth lever, unfortunately, it would no longer hold and operated just like you say, clunking and bouncing and eventually working to center and the feeding stopped.
So he took it apart and put it back the other way, and it holds fine, but it stiff to use.