If your engine has a flywheel magneto with a weak spark, you might well get better performance by moving the coil(s) closer to the magnets.
Clean the faces of the coil armature of any rust or paint etc. Loosen (but not remove) the screws which hold the coil in place. They should be only just loose enough to allow the coil to move, no more. Stick a single layer of insulating tape across the pole pieces and replace the flywheel - it should be down on the taper & engaging the key, but there is no need to do more than nip the nut up lightly.
Rotate it a couple of times to pull the coil into its closest proximity. Better still, if you can see the coil through a hole, shove it towards the magnet with your pinkie. If you can't see the screw heads with the flywheel in place, position the flywheel so the magnets are not in line with the coil & pull it off again. Tighten the screws & remove the tape. Replace the flywheel & check that it clears the pole pieces by listening for scraping noises!
No guarantees or liability, but it can't do any harm ..............
Regards,
Kim Siddorn. Mechanical Engineers build weapons, Civil Engineers build targets.