These diagrams are, in my opinion, a Must Have. Big, easy to read, laminated (great for putting beer bottles or coffee cups on), correct colours… blah blah, but really, just get one for your Guzzi.
For the record, I have no affiliation, and have not been asked for a testimonial: I bought one of these for each of my Tontis, with my own money, 100% impressed, and I now consider it a no-brainer.