What provides a retarded spark for starting the M14 engine?
———- Mags are not able to produce the required spark at near zero rpm. This is typical of radial engines that turn slow at starting. One thing to clear up here is that the M14P along with its radial engine brothers use BOOSTER COILS not Shower of Spark units! SOS units use the mags points to create the fire pulses. A booster coil has its own vibrator points and can produce a continuous spark that is delivered to the distributor block. Staggerwings, stearmans, Wacos, 195s use booster coils. On the 2 mag round motor like a 220 cont, PW 985 /1340, M14P, a booster coil unit is used which delivers High tension voltage thru a high tension lead to the distributor block, bypassing the mag’s coil altogether. The mags do not have a second set of points etc like a flat motor mag. Flat motors use a buzz box, shower of sparks box, whatever you want to call it, that feeds into the low tension p-lead side of the mag to excite the mag’s coil and use a retarded set of points in the mag. A lycomin
