He’s inspired by “crazy trains of thought”. People usually refer to thoughts as trains like “I just lost my train of thought.” But his “train of thought” is crazy. A Locomotive is the part of a train that pulls it, but loco means crazy in Spanish.
Loco = Crazy in Spanish
Locomotive = Vehicle that pulls trains
Loco motives = crazy motives, aka crazy trains of thought
This video is processing – it'll appear automatically when it's done.
This explanation hasn't yet been reviewed by the Rap Genius editors