av8tor,
almost any coil will work with cdi but the lower the inductance the better. kettering ign needs a large (lots of winds) primary winding and heavy iron core in order to build up and store the charge that it dumps through the secondary. all this is just a hinderance to cdi as it only uses the coil as a step-up transformer.

in the pic is a cut up echo cdi coil. in the middle is a tiny ferrite core and the bottom layer in the stacked windings is the primary which is only 27 turns. this thing only weighs only 12g! it wont do squat with a kettering ign but is ideal for cdi.

i think the echo and zenoah coils are the same and ch uses the oem coil on their zenoah conversions so i bet your coil is compatible with the ch circuit.

dave

ps-does your wife have a sister around 30 ?