Truccato literally means "made up" or "rigged." While it can refer to makeup on a face, in the context of a motor or engine, it means the machine has been tampered with or modified to perform beyond its normal limits.
In the song, the line "la tua moto dal motore che sento truccato" (your motorcycle with the engine I hear is souped up) uses the word to paint a vivid picture of a powerful, modified motorcycle roaring past.
This song describes a complicated and intense relationship, full of contradictions. The singer feels a powerful, almost addictive, need for his partner, comparing her effect on him to drinking salt water (acqua e sale). Just like salt water, she's something he craves but that ultimately leaves him feeling worse and wanting more. This creates a dynamic of push and pull, where pleasure and pain are deeply intertwined.
The lyrics paint a picture of a relationship where one person feels they are paying all the emotional costs (pene). He admits he needs her every day, yet he also feels it's not worth the trouble. He sees her as strong and surprising, even letting her take the lead, but he's also left waiting in a corner, feeling a mix of hurt and pleasure. The relationship is like a deep lake that could easily turn into a stagnant pond, highlighting its fragile and demanding nature.