hi there
dump your old coil!
get your self a pair of BMW r sieries coils "motor cycle".
they are 6volt and used in sieries to make them work at 12 volts.
i,been using them on all my 126 covertions , and never had any problems,
even when 24v starting!! some times i,ts got to be done"
moto-bins Lincolnshire, sell secondhand parts for bmws.
d'ont forget to get the mounting brackets for them""