Corrosion or a loose connection just adds to the resistance, as does higher compression. A 10 to 1 compression ratio has twice the resistance with a 0.030″ spark plug gap as a 5 to 1 ratio does. Retarding the spark for slower speed reduces pressure at the time of ignition and helps overcome the reduced output of the magneto at lower speed.
On polishing points – Whiteness of paper is enhanced by adding titanium dioxide to the mix which is an insolater. So do not use white business cards the polish points, regular cardboard works best. Steve Woods uses WD-40 with excellent results.
