* . . . See more on the Magneto Ignition System

(58-59 XLC and 58-69 XLCH) ^{1) 2)}
The magneto produces a high voltage discharge to the spark plug which is timed to each cylinder's compression stroke.
It also eliminated the need for a battery for ignition. ³⁾ as you can kick start or bump start the bike at about 2-1/2 MPH or less. ⁴⁾

• Components include a single induction coil, a rotating magnet (rotor), a condenser, a circuit breaker and a circuit breaker cam. ⁵⁾
• Ignition is timed when the front cylinder piston is 11/16“ / (45° of crankshaft rotation) before TDC on the compression stroke.
  Upon setting the proper timing adjustments at the factory;
  Timing alignment marks were stamped on the drive housing plate and rear edges of the magneto adapter plate for future timing adjustments. ⁶⁾
• A grounding circuit is connected to a button on the right handlebar (stop switch) that breaks the circuit to the ignition and stops the engine.
• Magneto mount changes:
  • (1958-1964) Magneto is mounted in a fixed position producing advanced spark timing only.
  • (1965-1968) Magneto is mounted on a movable plate allowing for spark timing retard.

AKA Retard Mag (Timing is mechanically advanced)
The Morris Auto Advance, is a small spring the goes under the Mag base.
Tighten up the nuts to create a slight drag, retard the spark for starting and the vibration + the spring will advance the unit. ¹⁰⁾

Morris Magneto (MM3) 11)