How do you set the points on a Tecumseh?

It depends on the engine. The newer ones use a magneto which contain solid state ignition, and if that goes bad, you change the entire magneto. For the older ones, you have to remove the flywheel to get to the magneto plate. Then you would need to remove the retainer clip holding the cover plate. The points are in two pieces, and there is a screw holding it in. If you loosen the screw, you can adjust the points. You may also want to sand the points some if they are rough or pitted. Then you can put everything back together.