A call to armatures

In these days of electronic ignition systems, the good old magneto may appear to be a throwback to a bygone era. But a healthy magneto is still a very viable source of sparks, and the heart of the matter is the armature, as Tim Thearle from TT Enterprises explains. “Magneto ignition is maligned by some, but it still provides the most efficient high tension current for the classic machines to which it was fitted. Even now, 60+ years after they were made I’m rebuilding many magnetos for their first time. So done properly they’ll outlast our generation easily!

The armature shown happens to be that from a Lucas magdyno, but the coil is similar in construction to the majority of magnetos. The rewound coil is insulated in a vacuum of winding lacquer before being baked for a minimum of 6 hours, then cleaned off and rebuilt into the armature. This process also ensures that the coil windings are held rigid in coils that rotate at half engine speed. It is a labour-intensive exercise but well worth the effort in achieving successful sparks for future decades.

Trouble free motoring with magneto ignition is achieved when attention has been given to replacing the original coil winding (which by now has compromised insulation and lacquer) with a well rewound coil. A replacement condenser is also built into the armature.”

Contact Tim on 0417 892 766 or by email: tim.thearle@bigpond.com