From what i've heard the Picco engines don't really enjoy being modified as much as some other brands, I think the Picco's are pretty much on the limit anyway, you just hurt fuel economy by modifying them.

Novarossi and OS engines take well to being tuned up and the gains are real, I've been told this by a top engine modifier from Italy, not sure how much truth there is in it, as with all things take with a pinch of salt.