Some DIY CDIs Want to build the "full" one with 1 to 1.5 microF main cap. USE "A" with "A" and "B" with the other "B", NOT ANY MIX! Higher values of capacitance around the 760 Ohm resistor = lower RPM when retardation is significant (4u7F=2700rpm, 5u64F (all caps) = 2200rpm, 3u3F would result in significant retardation at 3800rpm). The circuit with the 18 and 82 Ohm resistors has some timing correction above certain rpms (significant at 7750RPM). The thermistor circuit tries to vary appropriately with temp (Significant retard at 3300rpm). The Russian circuit with the potentiometer allows base timing adjustment. The Honda circuit has a cool place to put the kill-sw, buts it's input impedance is prob. too low and main capacitor C1+C2=1microF and only need to be rated at half voltage.