Depends on the magnet and keyway and key and the box itself given the key is in the same position on every crank which it's not... so basically there going to be a little different hence a mechanical advance/retardation would solve the inconsistencies... Like a choke lever to find the sweet spot... The early motorcycles had a twist grip on both sides to adjust... A cold and warm engine may require a little tweak... Then it doesn't matter and tune by seat of your pants once you know what random mix you happen to have likes... An example... Say I put a CDI one of the tall ones readily available on the 2012 gT5 motor that has the 12 o clock magnet made for the shorter SD CDI you can't get anymore... Or the 12oclock motor with the 1 O'Clock magnet with out having to cut the magnet... Unless 30° (+-) of timing difference doesn't matter then I'm retarted...