turning over by pedalling I get no spark
if I connect a 12v battery that's quite flat (reading 9v) to the system I can get a spark at the plug ie open points, earth backplate and plug, and connect live on and off to points wire = spark
if I try with a flatter 12v battery reading 5volts I get nothing
whats the lowest voltage I should be able to connect like above to get a spark? a torch battery?
is this a good way of determining how healthy the ignition coil is?