TT Back in the mists of time a cheap and reliable coil ignition alternative to the ageing K2F's was designed and manufacturer by Kirby Rowbotham, in Rugeley, Staffordshire UK.
This used a custom distributor housing, similar to yours, with contact points from the ever popular and available Ford Pinto OHC engine. The dizzy cap used was from a Fiat 500. The reasoning was that these other parts were freely available and of proven performance. Later versions evolved into the all singing and dancing electronic range we have now. After a long and successful association with the old bike movement, Kirby is now retired, by all accounts.
The USP of electronic ignition the Thorspark way is that there is no need for the additional expense of the modern housing, which alone represents a sizeable chunk of the cost to go electronic. Your old despised magneto does the job. Once fitted, (remember the magneto and its timing do not need to be disturbed) at first glance the machine looks to have its original magneto ignition. The magneto can be derelict inside, but as long as the armature turns the system will give consistent and reliable sparks. Poor magnetism, failed insulation, worn or non existent brushes, damaged slip rings, faulty coil and condenser are all of no consequence. All that is needed is a good set of bearings and an undamaged taper on the armature. It needs a battery powered supply, either from the machine or an external battery pack and power consumption is minimal. Available to suit 6 & 12 volt bikes.
The Thorspark system retains the mechanical advance system of the fitted magneto, and avoids the initial advance and starting problems of the more sophisticated electronic systems described above. It uses a wasted spark, so timing is identical on both cylinders, something not found on the majority of old worn maggys.
Swarfy.