Every thread I see on here where someone has jetting woes typically occurs after they use a JamesDean kit. All other makes/models seem to respond well to the kits except the Yammies. Constantly changing to blue/red needles, running lean, running rich etc. I took some advice from a fellow TT'er who's name will remain out of this and had my bike jetted to a "T". I couldn't be happier and no James Dean kit was necessary.