According to me,

Motive is an inner state that energies, activates, or moves and that directs behaviour towards goals.
A motive is restlessness,a lack ,a yen,a force.Once in the grip of a motive,the organism does something to reduce the restlessness,to remedy the lack,to alleviate the yen,to migrate the force.
where as,
Motivation is the complex force startingand keeping a person at work in an organization. Motivation is something that moves the person to action,and continues him in the course of action already initiated.