Hello, ive just bought a 80 gsx 750 with 42000 miles on the clock and absolutley love this beast. Pulls really well up to 5- 5.5 rpm where the engine stutters as if its getting to much petrol or air (or not enough). through first to third you can pull past this putter zone but in 4th or fifth if you twist the throttle back at these revs the bike will start to spit and back fire and i have to pull by the side of the road whereits fine once i set off again. has a mikuni set of carbs on it if that makes any difference.