The KX450F comes with three swappable ignition couplers: stock (green), mellow (black), and white (aggressive). The mellow, black coupler works well at the end of the day when the track is dry, hard-packed, and baked out. The white, aggressive coupler gives more of a lean, crisp power delivery with better throttle response and more overall power, but not so much that it feels uncontrollable. Meanwhile, the green, stock coupler fits right in the middle of the black and white options. While the couplers come in handy, having to stop and swap them out is a bit of an inconvenience in comparison to the on-the-fly mapping adjustments available on the Honda, KTM, and Husqvarna.