The 1970s Honda fours, i.e. the 350F, 400F, 500/550 Four, the early 650 SOHC, and the single-cam 750 are my favorite vintage Hondas. They are also the machines I learned the mechanic's trade on and thus are the most familiar to me. They're in my DNA. My all-time favorite is the 500/550 series. Here I have a page celebrating this model.