A correctly configured idle circuit is critical for good consistent starting, especially for a YZ426. "All stock settings" only works on certain year models at certain elevations. The 2000 model had jetting that was pretty well off the mark for most people, for example, while the '02 was better. All the '06's came with pilot jets that were at least a size too small to run right except near sea level, if that. So it varies. Besides, other than jetting, there aren't any settings to set, really.