on those old single magnet systems they typically don't have points, at least not in the case of old Briggs and Stratton engines. They run by letting the field build up and allowing it to collapse since there are no more magnets fueling it. While on a points system the points cut the circuit off at the peak of the primary coil output. Also a motobecane system is more advanced in design due to having three coils with a common ground (AC wye windings) that are all 90 degree's out of phase and two of which are 6v while on is 12, they can do some weird things when not balanced right. more complicated than you think.