There’s no error here.

The problem here derives from the fact that “motor” is used in English almost invariably to refer to rotary or linear electrical machines, and “engine” is used for other sources of mechanical power, of which there are many kinds (although most would be unsuitable in your context): internal combustion engines (petrol, diesel, etc.), external combustion engines (steam engines), and non-combustion engines (water wheels, water turbines, windmills, etc.).

To avoid the inelegant repetition of “motor” in Spanish, simply to bypass a somewhat arbitrary distinction in the English terminology, I suggest you rephrase it. For example:

... sistemas de engranaje impulsados por medios otros que motores eléctricos