Swap out the ignitor with a friends ignitor and see if that does the trick. Not too much more to check out. New spark plugs. The coils check out, what's left is the ignition pickup coil and the ignitor. Doubt it is the Hals device. Try unplugging the ignitor and applying some of that non conductive grease. Dangit if I can think of the name of it. Perhaps a pin within the ignitor's plug is not right? Long shot but who knows?
