Obviously you need to check the kill switch circuit in the hope that you will find the answer. Because the failure was somewhat progressive, though, you may find the insulation on the wires in the magneto secondary is breaking down, perhaps partly due to long exposure to moisture and repeated freezing, or just long-term chemical changes. I had a Villiers engine on a Supaswift mower that had a problem with magnetos dying of old age, even though it hadn't been frozen very often here in Melbourne. The first mag lasted 25 years, then the second-hand one I fitted lasted another 20. When the second one failed I finally saw reason and asked the city council to take the old Supaswift away - preferably far away. I hated that mower.
Last edited by grumpy; 01/05/09 05:54 AM. Reason: clarification
