PLATE 3P2279 - Caterpillar

Before making initial adjustments, check the engine and installation as you would during normal operation. See page 4.Carburetor Adjustment
CARBURETOR ADJUSTMENTS
1. Idle Adjustment Screw 2. Power Mixture Screw1. Set the power mixture screw (2) midway between "L" and "R".2. Turn the idle adjustment screw (1) clockwise all the way in, then out four turns.3. Set low idle speed on a cold engine. With the engine running, turn the low idle screw (1) to obtain recommended low idle speed (see the Engine Information Plate).Change the gas pressure delivered by the line pressure regulator to compensate for any change in heat content of the fuel. See your Caterpillar dealer for pressure settings.Linkage Adjustment
1. Disconnect linkage (1).2. Turn screw (2) counterclockwise until the throttle plate will close without touching the screw.3. Turn screw (2) until it touches stop (3) with the throttle plate closed.
LINKAGE ADJUSTMENTS
1. Governor Linkage 2. Throttle Stop Screw 3. Stop4. With the governor lever in the OFF position and the throttle plate closed, adjust the linkages and reconnect them. (If additional linkage adjustment is necessary, see your Caterpillar dealer.)5. On Vee engines adjust linkage so that both throttle plates open simultaneously.Gas Line Pressure
Gas line pressure must be regulated for use in engines. Naturally aspirated engines, using a line pressure regulator, require line pressure of 3 PSI to 20 PSI. A turbocharged engine must have greater working pressure available- 12 PSI to 20 PSI. Twenty PSI is the maximum line pressure which is easily reduced to a working pressure. If gas pressure exceeds 20 PSI, a second regulator will have to be used.Line Pressure Regulator
The line pressure regulator requires adjustment when the engine is installed, when the regulator is reworked, or when the heat content of the fuel is changed. A water manometer is used to set the regulator output gas pressure.1. Remove plugs (1) and (2) from the carburetor.
CARBURETOR
1. Air Pressure Manometer Plug 2. Gas inlet Plug 3. Power Mixture Screw2. Connect a water manometer between the two pressure taps.
LINE PRESSURE REGULATOR
4. Regulator Adjustment Plug A valve is used between the manometer and the carburetor to prevent water from being drawn into the engine during start up. Close the valve during cranking and start up, then open the valve when engine is running.3. Open the main gas valve.4. Adjust the gas pressure to support a 51/2 inch (14 cm) column of water, or to correct differential if fuel BTU is known.5. The regulator adjustment is made by removing plug (4) and turning the slotted cap clockwise to increase output pressure and counterclockwise to decrease pressure.6. Repeat this procedure for each carburetor.7. After these initial adjustments the engine can be started.Adjusting Line Pressure Regulator With Known BTU Fuel
1. With known BTU fuel, refer to a differential and BTU curve. See Form FE036044, or see your Caterpillar Dealer for pressure setting.2. Use the curve to find proper differential setting which gives the correct air fuel ratio.3. Follow procedure under line pressure regulator until adjusted gas pressure will support the proper differential