I bought a brand-new maroon KH 400 in October 1975 and kept it until June 1977. Middle cyclinder seized while bike was braking in, I do not think it is very well cooled, but dealer repaired under warranty. As I recall, it was a fun bike to ride: lots of torque in the mid-range, adequate braking, with moderate vibration on the highway. Longest ride I ever made on it was San Francisco to Eugene Oregon, it pulled OK going over the Siskyous, had to be in middle gears bu twould hold highway speeds OK. Seat uncomfortable for longer trips however, bring your preparation H. Front end is very light, tends to come up easily on fast starts.