Scuba wise from your description it sounds like the screw that keeps the motor down is not installed, not installed correctly or is too short. It is reached from the outside. After putting the motor in you installed the screw from the outside, it should go into one of the 4 openings in the side of the motor. If it does not the motor can work it’s way up till it will spin and not drive the slide in or out. Having the screw touch the side of the motor and not going into the hole is wrong and you will have a failure sooner or later.
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