0332275 JOHNSON CAP, Drive and commutator

Engine Specifications
Table 1
C12.9 Marine Engine Specifications
Cylinders and Arrangement In-line 6
Bore 135 mm (5.3 inch)
Stroke 150 mm (5.9 inch)
Compression Ratio 14.7 : 1
Aspiration Series turbocharged
Supercharger (if equipped)
Displacement 12880 cc (786 cubic inch)
Rotation (flywheel end) Counterclockwise
Control system Electronic
Method of fuel injection Common rail
Method of starting Electric starting motor
Method of cooling the turbocharged and supercharged air Low-pressure aftercooler (cooled by jacket water)
High-pressure aftercooler (cooled by jacket water) Electronic Engine Features
Cat C12.9 Marine Engines are designed for electronic controls. The integral on board computer controls the operation of the engine. Current operating conditions are monitored. The Electronic Control Module (ECM) controls the response of the engine to these conditions and to the demands of the operator. These conditions and operator demands determine the precise control of fuel injection by the ECM. The electronic engine control system provides the following features:
Automatic air/fuel ratio control
Engine monitoring
Engine speed governing
Injection timing control
System diagnostics
Torque rise shapingFor more information on electronic engine features, refer to the Operation and Maintenance Manual, "Engine Features and Controls" topic (Operation Section).Common Rail Fuel Injection System
The common rail fuel injection system performs the following functions:
Meter the fuel
Pressurize the fuel
Time the fuel injectionThe fuel pump pressurizes the fuel. The fuel pump pumps the fuel to the common fuel rail. The common rail fuel injectors inject fuel into the cylinders at a precise time. The fuel is injected into the cylinders with the appropriate volume. Electronic sensors on the engine determine time and volume of fuel injection.Engine Diagnostics
The engine has built-in diagnostics to ensure that all the components are functioning properly. In the event of a deviation from the programmed limits, the operator will be alerted to the condition by the following: "Diagnostic" lamp (OEM installed), MECP1 (optional), and displays (OEM installed). Under certain conditions, the engine horsepower and the vessel speed may be limited. A Cat electronic service tool may be used to display the diagnostic code.Diagnostic codes are logged and stored in the ECM. For additional information, refer to the Troubleshooting manual.Engine Speed Governing
The ECM provides electronic governing that controls characteristics of fuel injection to maintain the desired engine rpm. The functionality of electronic governor is similar to the Cat mechanical governor, but the electronic governor includes more features.Engine Cooling and Lubrication
The cooling system consists of the following components:
Coolant expansion tank
Engine oil cooler
Fuel cooler
Gear driven sea water pump
Heat exchanger
High-pressure aftercooler
Intercooler
Jacket water pump
Jacket water temperature regulator
Low-pressure aftercooler
Optional transmission oil cooler (shipped separately)
Optional wet (sea water) exhaust riserThe engine lubricating oil that is supplied is cooled by an engine oil cooler. The engine lubricating oil is also filtered. Bypass valves provide unrestricted flow of lubrication oil to the engine components during the following conditions:
High oil viscosity
Plugged oil cooler or plugged oil filter elements (paper cartridge)Fuel System
The fuel system consists of the following components:
ECM controlled off-engine electric priming pump
Electronically controlled injectors
Fuel cooler
Fuel rail
High-pressure common rail fuel pump
Off-engine primary fuel filter and water separator
Secondary fuel filter
Transfer pump
Water-in-fuel sensor (optional)The electric priming pump primes the system with fuel after a fuel system service. The electric priming pump also primes the system with fuel if the engine has not run for an extended period.Engine Service Life
Engine efficiency and maximum utilization of engine performance depend on the adherence to proper operation and maintenance recommendations. In addition, use recommended fuels, coolants, and lubricants. Use the Operation and Maintenance Manual as a guide for required engine maintenance.Expected engine life is predicted by the average power that is demanded. The average power that is demanded is based on fuel consumption of the engine over a time. Reduced hours of operation at full throttle and/or operating at reduced throttle settings result in a lower average power demand. Reduced hours of operation will increase the length of operating time before an engine overhaul is required. For more information, refer to the Operation and Maintenance Manual, "Overhaul Considerations" topic (Maintenance Section).