I have a 08 yzf 450 that starts hard only when it sits for a day or 2. if i twist the throttle once or twice is likes to fire up much faster. one other issue is from a steady 3/8 throttle and down to an idle it will purr then have a quick skip or hiccup. at half to full it has no skip. my valves are adjusted correctly and the carb is clean. im assuming that it needs to be richened on the bottom end? what do i change to give it more fuel to help start and give more fuel on the bottom. thanks for any advice i also have an 06 250f and it fires up in 1-3 kicks no matter how long it sits.