Phil did explain it to me. I wouldn't go into it here where people who regularly rebuild 750 cranks are far more qualified than myself to comment. The 750 cranks are sometimes, often, ?, not 360°. The splined centre piece was pressed into the smooth webs creating splines in the process. There is apparently some leeway when you re-assemble.Innaresting about out of phasing on SF cranks - with that rammed splined 'undisassemblable' centre I woulda thought the factory could get it right. Not quite sure how you'd correct it if you reuse the same centre and the same webs, because the splines are already aligned incorrectly. SFCs are on a non-splined sold pin as are the triples. Getting it right without a jig like Red's isn't easy. I don't mind if my 270 is 269 or 271 - as long as you compensate the cam and ignition accordingly.
I'm certain that, all else put aside, a lot of the different vibrations from one 750 to the next can be attributed to crank phasing.
Paul









