The sign for "motor" is the same sign as ENGINE/MACHINE/FACTORY.
That is right, this one little sign can be interpreted many different ways depending on what you sign in the rest of your sentence.
Form modified claw hands (the large knuckles are straight but the middle and small knuckles are bent). Interlock your hands as if they were the teeth on two interlocking gears in a machine. Keeping your arms in place, move your wrists so that the hands move upward and and downward a couple times as if showing the movement of gears in a machine.
MOTOR / ENGINE / FACTORY / MACHINE:
Notes: