Old B&S engines, the ones made before electronic ignition, are notorious for getting oxidation on the ignition points if they're not run regularly. Pull the flywheel and burnish the points with a clean pencil eraser- - - -it has just enough abrasive to polish the contacts without leaving deep scratches. Then loosen the attaching screws for the ignition coil and use a 3X5 index card to set the gap between the coil and the flywheel magnet. Set the point gap (I think it's .020") and button everything up. That aluminum flywheel timing key is made of soft metal for a reason- - - - -don't get tempted to replace it with a steel key. Do all the above, and you'll have a hot spark that happens at even very low cranking speeds. You can pull the spark plug and spin the flywheel by hand and still get a good spark.
Jerry
