Hi Daz, I use the 600s in my bikes as I ride choppers, there plenty fast enough for me and very predictable, I used a fazer 600 in my last build which incorporated an airbox and it runs perfectly, the bandit dose not have room for an airbox so I need to use either flat slides or filters. I read your last answer about the airbox rubbers and sock filters. I now realise the RS carbs are now only really available for the bigger engines so will try your idea. So when you used the airbox rubbers and filter socks did you fit a dyno jet kit then take it to be set up on a dyno?