XR 600 ran dual carbies 1985-1987, we didn't get the 1987 model in Oz for reasons unknown. First single carb was 1988 & had a number of changes like 18" rear wheel, smaller rear hub (!!), nikasil liner in cylinder and minor cosmetic changes. All good bikes; but were heavy and sometimes suffered from weak stators making hard to start. The twin carby models went a bit harder but were a hassle to tune carbs.