3V1-87121-0 Tohatsu POWER HEAD GASKET SET

The disconnect switch, if so equipped, must be in the ON position for the electrical system to function properly. There will be damage to some of the charging circuit components if the engine runs with the disconnect switch in the OFF position.
The starting circuit is in operation only when the start switch is activated.The charging circuit is connected through the ammeter. The starting circuit is not connected through the ammeter. Charging System Components
Alternator
Illustration 1 g00292313
Delco-Remy Alternator (1) Regulator. (2) Roller bearing. (3) Stator winding. (4) Ball bearing. (5) Rectifier bridge. (6) Field winding. (7) Rotor assembly. (8) Fan.The alternator is driven by vee shaped belts from the crankshaft pulley. This alternator is a three-phase, self-rectifying charging unit, and the regulator is part of the alternator. The rotor assembly has many magnetic poles. There is a space between the opposite magnetic poles. The poles have residual magnetism which produces a small amount of magnet-like lines of force between the poles. A small amount of alternating current is produced as the rotor assembly begins to turn between the field winding and the stator windings. This alternating current is produced from the small magnetic lines of force that are created by the residual magnetism. The alternating current changes to direct current. This happens as the alternating current passes through the diodes of the rectifier bridge. Most of the current charges the battery. Some of this current supplies the low amperage circuit, and the remainder of the current is sent to the field windings. The DC current flow through the field windings increases the strength of the magnetic lines of force. The stronger lines of force increase the amount of the alternator current that is produced in the stator windings. The increased speed of the rotor assembly also increases the current and voltage output of the alternator. The voltage regulator is a solid-state electronic switch. This switch feels the voltage in the system. The switch turns on and off multiple times in a second. This controls the field current for the alternator which will produce the necessary voltage output.Starting System Components
Solenoid
A solenoid is a magnetic switch that performs two basic operations:
The solenoid closes the high current starter motor circuit with a low current start switch circuit.
The solenoid engages the starter motor pinion with the ring gear.
Illustration 2 g00292316
Typical solenoid schematicThe solenoid switch is made of an electromagnet around a hollow cylinder. There is a spring loaded plunger inside the cylinder. This plunger can move forward and backward. When the start switch is closed and electricity is sent through the windings, a magnetic field is created. This magnetic field pulls the plunger forward in the cylinder. This causes the shift lever to engage the pinion drive gear with the ring gear. The front end of the plunger makes contact across the battery and motor terminals of the solenoid. The starter motor begins to turn the flywheel of the engine. When the start switch is opened, current no longer flows through the windings. The spring pushes the plunger back to the original position. While the plunger moves back to the original position, the pinion gear moves away from the flywheel.When two sets of windings in the solenoid are used, one set of windings is referred to as the hold-in winding, and the other set of windings is referred to as the pull-in winding. Both sets of windings have the same number of turns around the cylinder. This pull-in winding uses a wire with a larger diameter. A wire with a larger diameter produces a stronger magnetic field. When the start switch is closed, part of the current flows from the battery through the hold-in windings. The remainder of the current flows through the pull-in windings to the motor terminal. The current then flows through the motor to ground. When the solenoid is fully activated, the current is shut off through the pull-in windings. The smaller hold-in windings are in operation for an extended period of time when the engine is started. The solenoid will take less current away from the battery. Heat that is produced by the solenoid will be kept at an acceptable level. Starter Motor
The starter motor is used to turn the engine flywheel. The flywheel must reach a certain speed in order to start the engine.The starter motor has a solenoid. When the start switch is activated, the solenoid will move the starter pinion. The starter pinion will engage with the ring gear on the flywheel of the engine. This will happen before the electric contacts in the solenoid close the circuit between the battery and the starter motor. When the circuit between the battery and the starter motor is complete, the pinion will turn the engine flywheel. A clutch gives protection for the starter motor. The clutch prevents the engine from turning the starter motor too fast. When the start switch is released, the starter pinion will move away from the ring gear.
Illustration 3 g00292330
Starter motor cross section (1) Field. (2) Solenoid. (3) Clutch. (4) Pinion. (5) Commutator. (6) Brush assembly. (7) Armature.Other Components
Circuit Breaker
Illustration 4 g00281837
Circuit Breaker Schematic (1) Reset button. (2) Disc in the open position. (3) Contacts. (4) Disc. (5) Battery circuit terminals.The circuit breaker is a switch that opens the battery circuit if the current in the electrical system goes higher than the rating of the circuit breaker. The electric current through the circuit breaker is completed with a metal disc. This metal disc is activated by heat. The metal disc will become hot if there is too much current in the electrical system. This heat causes a distortion of the metal disc. This distortion of the metal disc opens the contacts. When the contacts open, the circuit breaks. An open circuit breaker can be reset after the temperature has dropped. The contacts must be closed in order to reset the circuit breaker. Push the reset button in order to reset the circuit breaker.