Honda’s first four caused a storm in 1969 but now killed dead by most 550’s. Longevity’s its best feature, 100,000 miles possible, though many faltered at 50k. Look for cracked crankcases from snapped chain, oil leaks from head gasket and gearbox seals, rattly clutches and ruined gearbox selectors. Development consisted of decreasing the power and increasing the mass (ending with the K7 at 500lbs), which makes the K0/1 almost worthy of their classic status but later models the bargain buys.
1969-78, 749cc OHC four, 67/63hp, 125/120mph, 50/45mpg