Picture this: It’s the late 1970s, and you’re a Honda engineer working for the man himself, Soichiro Honda. It is a truth, universally acknowledged, that the Old Man absolutely, unequivocally hates two-strokes. However, he loves testing his company’s engineering mettle in motorcycle racing—and also, it's the time when two-strokes rule the world. Additionally, there's that teensy conundrum that most racing series tend to have: A set of rules that must be followed. What do you do?
If you’re Honda, you get to work engineering a new four-stroke, four-cylinder machine. According to the existing rule book, four is the maximum number of cylinders a bike can have, 500cc is the max displacement, and the bike must also be naturally aspirated. With two-strokes of the era hovering around the 120-horsepower mark, it’s certainly a difficult puzzle to work out—but impossible?