I've just bought an old Victa 80 Super 24 2-stroke mower. It was very hard to start and after running for about 20mins it would cut out and not start again until the mower had cooled down.
I replaced the spark plug and checked and cleaned the points, this made no difference.
Then I bought and fitted an Atom Electronic Ignition Module - now I don't get a spark at all.
One thing I'm not sure about is if I've got the wiring wrong. I know that the primary wire is connected correctly but there is another wire from the points which clipped onto a tag on the carby and I couldn't work out what this was for. I've treated this as if it is a switch wire as shown in the Atom wiring diagram.
Someone suggested that the coil is knackered and the Atom instructions suggest filing the stator plate to move the coil closer to the flywheel magnets.