While the words "Engine" and "Motor" are somewhat interchangeable, "Engine is used to describe "fuel burners" while "Motors" usually mean "Electric"

When an engine starts backward, it is usually a sign of it having too much fuel in the mixture - often from having been over-primed.

Sometimes, when the engine is running backward, opening and closing the throttle can make it "Hiccup" and reverse direction. Usually, the engine just dies and needs to be restarted