0581321 EVINRUDE LEAD, Upper

Solid State Magneto (Altronic)
Illustration 1 g00743710
Magneto
(1) Alternator
(2) Stator The main components of the Altronic magneto are alternator (1) and stator (2). The alternator generates electricity. The stator distributes the electricity. There are no brushes or distributor contacts.
Illustration 2 g00579848
Cross section of an Altronic magneto
(3) Rotor
(4) Vent
(5) Speed reduction gears
(6) Pickup coil
(7) Drive tang
(8) Storage capacitor
(9) Rotating timer
(10) Silicon controlled rectifier (SCR)
(11) Output connector The magneto's drive tang (7) is driven by the engine. The drive tang is attached to a shaft which turns the alternator's rotor (3). Rotation of the rotor causes rotation of speed reduction gears (5) and rotating timer (9). The power from the alternator charges storage capacitor (8). There is a separate pickup coil (6) and a separate silicon controlled rectifier (SCR) (10) for each cylinder. As the rotating timer passes over the pickup coils, a pulse from each coil activates each corresponding SCR in sequence. Each SCR releases the energy that is stored in capacitor (8). This energy leaves the magneto through output connector (11) and the ignition wiring harness to the ignition transformers. The transformers increase the voltage to the level that is needed to fire the spark plugs.Solid State Magneto (Fairbanks Morse)
Illustration 3 g00662676
Cross section of a solid state Fairbanks Morse magneto
(1) Plug
(2) Coil
(3) Plate and power board assembly
(4) Distribution board
(5) Capacitor
(6) Alternator housing
(7) Coil
(8) Rotor
(9) Silicon controlled rectifier (SCR)
(10) Connector plug Rotor (8) is driven by the engine through a drive coupling. The rotor moves by each coil (7) in order to produce voltage. The alternating current is sent through a rectifier which converts alternating current into direct current. The voltage is sent to the silicon controlled rectifier (SCR) (9) for the cylinder that will fire. Energizing the SCR enables the voltage that is stored in capacitor (5) to be released. The voltage goes through distribution board (4) to the transformer. As the rotor moves past each coil, the same electrical impulse is developed.Spark Gap Magneto
Illustration 4 g00662340
Cross section of a spark gap magneto
(1) Distributor's disc
(2) Cam
(3) Distributor's gear and shaft assembly
(4) Transformer
(5) Coupling
(6) Rotor
(7) Condenser
(8) Contact points
(9) Rotor
(10) Brush and spring assembly Transformer (4) has a primary coil that is made of a heavy wire. One end of the primary coil is connected to ground on the transformer's core. The other end of the primary coil is connected to contact points (8).Rotor (6) is a permanent magnet. When the rotor turns, electrical energy is produced in transformer (4). This will produce electricity in the wires.When the voltage in the primary coil is at the highest peak in the alternating current's cycle, cam (2) opens contact points (8).The contact points open in order to break the electric circuit. The flux around the wires of the primary coil will suddenly collapse through the primary coil. This produces peak voltage in the primary coil.At peak voltage, the position of the distributor's disc (1) completes the circuit through the brush and spring assembly (4). The voltage travels to the distributor's block and through the low tension leads to the ignition transformers.Condenser (7) prevents a spark that can cause damage to contact points (8). The electrical energy which normally makes a spark across the gap in the contact points goes into the condenser. When the contact points close, the electrical energy in the condenser moves back into the primary coil in order to provide voltage.Impulse coupling (5) is used to cause an increase in the rpm of the rotor. When you start the engine the coupling is engaged. This will produce a stronger spark while the engine is started. The coupling is not engaged during normal engine operation.Ignition Transformer
Illustration 5 g00679230
Standard transformer
Illustration 6 g00663208
Integral Altronic transformer
An ignition transformer for each cylinder enables the ignition system to use low tension (voltage). Low voltage is sent to the transformers. The transformers increase the voltage to the high tension that is needed to fire the spark plugs.In an ignition system that uses high tension, the loss of current through the wiring can be substantial. Routing of several wires that conduct high tension increases the chance of an insulation failure which can result in grounding of the current. Also, the current in the wiring can be affected in a manner that is similar to the current in a transformer. This can result in a crossover of the current between the leads. The crossover can cause a loss of power and misfire. An ignition system that uses low tension has these advantages over a system that uses high tension:
Line loss through the wiring is reduced.
The possibility of insulation failure and grounding of the current is reduced.
The possibility of crossover is reduced.For proper operation, the terminals of the transformer must be clean and tight. The negative transformer terminals have a "−" mark. These terminals are connected together and the circuit is grounded.Spark Plugs And Adapters
Illustration 7 g00663105
Spark plug and adapter
(1) Cover
(2) Spark plug wire
(3) Seal
(4) Spark plug adapter
(5) Spark