A theoretical question please.
If a bike eas on 6volts and the condenser installed.
If this bike is converted to 12v using the same condenser, will the higher voltage across the existing condenser damage it please?
Unlikely
Agree, almost certainly not.
Fair enough, just a thought.
S---s law then that my condenser chose to fail after a 12v conversion.
Bad timing !!
As a result of the way they work, electrolytic capacitors used as ignition condensers have a finite lifetime - typically 10 years. In this case, it may be that the 6V condenser had started to fail and the switch to 12V simply pushed it over the edge. If the age of the current condenser is unknown in what is probably at least a 50 year old bike, it's worth replacing it by a new one to ensure an optimum spark.
Done this already, with a Lucas/Walsall replacement.
However , I'm keeping the old one and removing the guts from it and placing a 4mm bolt(to support the cb spring+ low tension wire) in resin in the old carcass.
This way allows me to retain the current cb points and have a car condenser under the seat near the coil.
Most ignition condensers works for both 6 and 12 Volts, positive or negative earth.
Never heard of use of electrolytic condensers in contact breaker systems before. They are polarity sensitive and have too large capacity for use over the contact breaker.
Only electrolytic condensers I know of on British motorcycles is the blue 2MC used to enable starting and running without battery. Came sometimes in second half of the sixties.