Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Could be that Boyer’s engineers have optimised/improved on Honda’s probably conservative spec (itself constrained by the relatively crude mechanical advance) or perhaps the basic module and timing profile is sold by Boyer for a number of motorcycle models including the CB750 and is therefore a compromise to suit a range of specifications...