SPACER 2724978 - Caterpillar

An engine failure may occur if the air/fuel ratio is not appropriate for the fuel and for the operating conditions. The service life of the turbocharger, of the valves, and of the other components may be reduced.Ensure that the carburetor is adjusted properly so that the air/fuel ratio is correct. An emissions analyzer must be used in order to measure exhaust emissions. An emissions analyzer that can measure NO and NO2 separately must be used in order to check the air/fuel ratio. The emissions analyzer that is used for calibration of the engine must be accurate within 10 percent of a standard while the engine is running at the desired emissions level for NOx. Calibrate the emissions analyzer for the NO and for the NO2 in order to maintain this accuracy level. If any changes are made to the engine timing or to the settings of the wastegate, the ratio of air to fuel must be checked. The ratio of air to fuel must then be adjusted with an emissions analyzer.In order to maintain the proper emissions, recalibrate the O2 sensor.For information on adjusting the carburetor, refer to the Systems Operation/Testing and Adjusting, "Carburetor (High Gas Pressure) - Adjust", or refer to the Special Instruction, "Installation and Initial Start-Up Procedure".