The coils and the condensers on these motors are almost always good. Like Mumbles said, "clean and polish the points first". While you have the flywheel off, polish all of the contacts as well, and you may find that the spark issue is solved.

Your HD-25 may have the open brass sparkplug terminals. These assemblies have a brass collar that goes over the wire end, a brass terminal that connects the wire end to the sparkplug, and a tiny Phillips head brass screw that holds the terminal on and screws into the end of the copper core wire for contact. Take those assemblies off and polish up all parts. You can nip the ends of the wire for a ‘new’ connection to the ignition wire and reinstall the tiny brass screw. If the plug wires are brittle and cracked, they can be replaced but that is another topic.