Sorry to add more detail:
Less of an air gap would result in less reluctance in the magnetic circuit through the armature or iron core. Less reluctance means a greater flux density in the iron core, so more flux or magnetic lines of force cutting the magnetos primary coil, so primary coil would produce a larger magnetic field, when the electronic module opens (in my mind it is just an electronic switch) the now larger primary field, due to the smaller air gap collapses across the secondary winding this would induce a higher voltage than before resulting in a stronger arc across the plugs gap.
You need 3 ingredients present to induce a voltage.1.Conductors 2. Magnetic field. 3. relative movement.
Last edited by mark electric; 31/08/12 07:51 PM. Reason: spalling
