Lucas K2F Magneto

A nice piece of machinery. When I got the bike the sparks disappeared after approx. 5 min, and reappeared when the machine had cooled. Started checking for electronic ignition prices. Careful examination of the magneto revealed problems with a wire coming out of  the armature winding. When the magneto was cold there was contact, when hot the expansion caused a break in the wire. As it was on the outside of the armature near the condenser it was possible to fix. Has since been working fine for a long time and looks like it should last another 50 years. Keeping all the bike's old electrics is a goal in itself. This K2F magneto uses the manual advance control.

Points & camring

Timing between the cylinders was not right, caused by a worn camring. A new camring combined with some patient adjustment has put it right. On any K2F always check the camring for wear. Can be spotted if it's not possible the get the right point gap in both positions (and the engine seems to lack some power). The timing advance is done by rotating the camring via a cable and lever on the handlebar (original for The Golden Flash would be the automatic centrifugal advance drive gear, mounted on the magneto shaft. The manual control was fitted to the SR & RR).

Timing test

To set the magneto timing accuracy between cylinder 1 & 2, a strobe was used in conjunction with 180 degree marks painted on the drive gear. Use a drill to drive the magneto. The plugs are wired and attached to the magneto body. Watch out for electric shock, it will make you spark at the slightest turn.