G'day Grant,
looking at your ignition diagram, the capacitor would have to be polarised, i.e. have a positive terminal, as it is applied to rectified dc voltage.
I will let you know, this the first time I have been exposed to this set up with a feed coil.
The normal mower set up, the capacitior is applied to ac voltage, so would not be a polarised type.
Just something I noticed.
