If it were my generator, I would call the company to get a replacement motor, or switch to an aquarium bubbler to stir the water.
Why waste the money to buy a new generator? They all work on a similar current controlled electrolysis.
IMO, this Silvertron Elite is the greatest improvement in CS Generators since sliced bread.
It starts at 20ppm and goes up from there, displays voltage, current & a completion bar. It stores all settings even after power off, even has an optional 1 oz silver bar. https://www.youtube.com/watch?v=lOKnp9Y54Ls