I have entered the specs for the 1977 KZ750 and they should appear in a couple of days. Manufacturers specs are 55hp@7000 and 6kg-m@3000 (43.4lb-ft). The engine used balance shafts to cancel vibrations and it was one of the nicest ´bikes I have owned, I sold it in 1979 with 80 000km on the clock (after an accident with a car).