GASKET 8H0619 - Caterpillar

Check the fuel pressure to the gas pressure regulator. For low-pressure gas, fuel pressure of 10 kPa (1.5 psi) to 34.5 kPa (5 psi) is required for the gas pressure regulator.Pressure of the Fuel Supply To the Carburetor
The gas pressure regulator maintains a pressure differential between the air and the fuel that is supplied to the carburetor. After setting, the gas pressure regulator will maintain the pressure differential in response to changes in the air pressure.Use a water manometer for measuring the pressure differential. Obtain the measurement when the engine is operating at high idle rpm. After a load is applied, the fuel pressure will usually decrease by approximately 0.1 to 0.25 kPa (0.50 to 1 inches of H2O). If the performance of the gas pressure regulator is erratic, the gas pressure regulator may require service.Natural Gas
Set the pressure of the fuel supply to a maximum of 1 to 1.2 kPa (4 to 4.5 inches of H2O) HIGHER than the ambient air pressure.Negative Gas Pressure Regulator (Propane)
If the engine has a dual fuel system with a negative gas pressure regulator for propane, set the pressure of the fuel supply to −0.37 −0.06 kPa (−1.5 0.250 inches of H2O) LOWER than the ambient air pressure.Liquid Propane Regulator and Vaporizer
If the G3406 engine is equipped with a regulator/vaporizer for a liquid propane application, the regulator controls the pressure to the carburetor and no adjustments can be made.