Ever since the temperature has been dropping outside, my 01 yz250f is doing something wierd. When i hit the throttle and let off, it still seems to stay up in the rpms until i quickly blip it again and it comes to a normal idle . My throttle isn't sticking or anything, that is all working properly. I remember with my r/c cars, if the mixture was too lean, when letting off the throttle the car would continue to coast and rev until blipping the throttle again. My guess is that since its getting colder, the carb is getting leaner? It also pops now on decel as well. I guess I will try backing the fuel screw out a 1/4 turn at a time. As far as this throttle/idle issue though, what do you guys think it is?