Air gap checking squareness

Hi,
The magnets should be used to "pull" in both legs of the armature simultaneously. The gap can be achieved by using an ordinary business card, putting it between the flywheel and armature legs, rotating flywheel to position magnets centered between legs, losing to achieve airgap and carefully tightening. Some people will mount the armature as far from the flywheel as possible, rotate into position, loosen screws holding the armature just enough to let it be attracted by the magnets and tightening. The card is then removed and the flywheel rotated by hand to check for rubbing.
Peace,
Clarke
PS All this is easier with plug removed.