People who have problems with their Lucas magnet should take a look at www.brightsparkmagnetos.com
The Willie Roots behind that site have devised a chip that can put the performance of a Lucas magnet back on track. The Easy Cap Condenser. The hi-tech ceramic condenser replaces the one that lives deep in the dark bowels of the magnet.
And the result is staggering. An Easy Cap Capacitor costs around 25 pounds. And works.