0318207 JOHNSON LEVER, Throttle

Grounding Practices
Proper grounding is necessary for optimum engine performance and reliability. Improper grounding will result in uncontrolled electrical circuit paths and in unreliable electrical circuit paths.Uncontrolled electrical circuit paths can result in damage to main bearings, to the surfaces of crankshaft journals, and to aluminum components. Uncontrolled electrical circuit paths can also cause electrical activity that may degrade the engine electronics and communications.Ensure that all grounds are secure and free of corrosion.The engine alternator must be grounded to the negative "-" battery terminal with a wire that is adequate to carry the full charging current of the alternator.For the starting motor, do not attach the battery negative terminal to the engine block.Ground the engine block with a ground strap that is furnished by the customer. Connect this ground strap to the ground plane.Use a separate ground strap to ground the battery negative terminal for the control system to the ground plane.If rubber couplings may connect the steel piping of the cooling system and the radiator, the piping and the radiator can be electrically isolated. Ensure that the piping and the radiator are continuously grounded to the engine. Use ground straps that bypass the rubber couplings.
This engine is equipped with a 24 volt starting system. Use only equal voltage for boost starting. The use of a welder or higher will damage the electrical system.
Unlike many electronic systems of the past, this engine is tolerant to common external sources of electrical noise. However, electromechanical alarms can cause disruptions in the power supply. The engine's electronic control module (ECM) is powered through two power sources. One power source comes directly from the battery through a circuit breaker. The other power source comes through the keyswitch and another circuit breaker. Disconnect the power with the disconnect switch for the main power when you are working on the engine's electronics. The switch is by the battery box.Electrical Components
Starting Motor Protection
The starting motor is protected from damage in two ways:
The starting motor is protected from engagement with the engine when the starting motor is running. The control feature will not allow engagement of the starter motor if the speed is above 0 RPM.
After the engine starts, the starter motor is protected from continued operation if an operator holds the key in the "Start" position. This is accomplished by disengaging the starting motor solenoid after engine speed reaches 300 rpm.Magnetic Pickup
Illustration 1 g00285114
Schematic of Magnetic Pickup (1) Magnetic lines of force. (2) Wire coils. (3) Gap. (4) Pole piece. (5) Flywheel ring gear.The magnetic pickup is a permanent magnet generator with a single pole. The magnetic pickup is made of wire coils (2). The coils go around a permanent magnet pole piece (4) .As the teeth of the flywheel ring gear (5) cut through the magnetic lines of force (1) around the pickup, an AC voltage is generated. The frequency of this voltage is directly proportional to engine speed. Circuit Breaker
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. A metal disc that is activated by heat is a contact point that completes the electric circuit through the circuit breaker. If the current in the electrical system gets too high the metal disc will get hot. This heat causes a distortion of metal disc. The disc opens the contacts. The disc breaks the circuit.
Find and correct the problem that causes the circuit breaker to open. This will help prevent damage to the circuit components from too much current.