I am shifting between 5kand 6k as I am still very leary of getting on to much. My bike still has the choppy sound after it warms up and it idles around 1100. The bike has the yoshi slipons that came with it. With 12,800 miles maybe I need to change plugs and air filter? I have been working alot after I got the bike really haven't had much time to do to much maintenance checking yet,but I am very happy so far.