OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Four Stroke Lawn Mower Frames New member mower questions for restoration

Sounds like it was the primary wire [or primary earth wire] that broke. Not that uncommon back in the day, as these are single strand wires, and won't take a lot of flexing. Often they break flush with the edge of the coil too, which makes repair difficult, or sometimes impossible.

JulianB, did you fit a complete late model Magnetron coil [as grumpy refers to], or just an aftermarket electronic trigger module?

Here's a diagram of the carby pin and washer in the right position, from the Briggs Service Manual for that model:


And here's the critical part of the tank top that has to be checked for flatness, shown as the shaded bits in the close-up:


If the feeler gauge will fit under the straightedge, the tank is out of spec. It usually can be repaired as grumpy describes.