Throttle Linkage
Adjust the throttle linkage according to the engines Specifications.
Load Adjusting Valve
| Tools Needed | ||
| 391-8170 EMISSIONS ANALYZER TOOL GP - (Bluetooth Module) (1) | 1 | |
| 393-0673 EMISSIONS ANALYZER TOOL GP (1) | 1 | |
| 1U-5470 Engine Pressure Group | 1 | |
| ( 1 ) | Either analyzer may be used. |
The load adjusting valve affects the air/fuel ratio. The valve determines whether the mixture is rich or lean. The following factors are influenced by the air/fuel ratio:
- Fuel consumption
- Engine power output
- Engine stability
- Engine component life
- Deterioration of lube oil
After the gas pressure regulator, the load adjusting valve regulates the amount of fuel to the carburetor. The load adjusting valve is initially adjusted in order to provide sufficient fuel for engine start-up. After the engine is running, the load adjusting valve is used to obtain the desired exhaust emissions.
The most accurate method of adjusting the air/fuel ratio involves the use of an emissions analyzer. This method consumes the least amount of time as well.
- Remove plug (1) from the exhaust elbow. Install the sensor for the emissions analyzer.
 | |
| Illustration 1 | g00820364 |
(1) Plug in the exhaust elbow | |
- Use the 1U-5470 Engine Pressure Group to measure the inlet manifold air pressure. Refer to Testing and Adjusting, "Manifold Air Pressure Sensor".
The load can be estimated by the inlet manifold air pressure. For information on estimating the load, refer to Special Instruction, SEHS7341.
For generator set engines, the load can be determined by the electricity that is generated.
- Turn load adjusting valve (2) clockwise until the valve is fully closed. Be careful not to overtighten the load adjusting valve.
 | |
| Illustration 2 | g00820354 |
(2) Load adjusting valve | |
- Turn load adjusting valve (2) counterclockwise for 3.5 to 4 revolutions.
- Start the engine. Operate the engine with a partial load and allow the engine operation to stabilize.
- Use the emissions analyzer to check the levels of O2 and NOx.
- Slowly adjust the load adjusting valve until the desired exhaust emissions are obtained.
For a leaner mixture of air and fuel, turn the load adjusting valve clockwise. To richen the mixture of air and fuel, turn the load adjusting valve counterclockwise.
- Increase the load. Adjust the exhaust bypass valve, if necessary. Refer to Testing and Adjusting, "Exhaust Bypass Valve".
- Monitor the position of the throttle plate, the desired engine rpm at full load, and the exhaust emissions. Continue to adjust the load adjusting valve and the exhaust bypass valve. Make adjustments until the engine is operating at full load with a throttle angle of approximately 70 degrees.
 | |
| Illustration 3 | g00942890 |
Angle of the throttle plate | |