FM684585 Force DECAL, TOP REAR

Gas Main Line Pressure
On turbocharged engines gas line pressure to the line pressure regulator (1) should be between 12 and 20 PSI for proper control of pressure to the carburetor regulator. On naturally aspirated engines gas line pressure to the line pressure regulator should be between 3 and 20 PSI. When gas line pressure extends beyond the limits indicated above, other commercially available methods of controlling the pressure will be required. See your Caterpillar dealer.
LINE PRESSURE REGULATOR
1-Line pressure regulator. 2-Plug in manometer connection opening.Checking Gas Pressure
Line pressure regulator (1) may require adjustment when the engine is installed or when the regulator has been reconditioned. A water manometer is required to check the gas pressure delivered from the line pressure regulator to the carburetor regulator (3) to see if adjustment is required. The manometer should be connected as indicated for turbocharged engines and naturally aspirated engines as follows: Turbocharged and Naturally Aspirated Engines Equipped with Impco Carburetors: To check gas pressure between line pressure regulator (1) and carburetor (4) remove the plug (3) and connect one end of the manometer to the plug opening. Remove the gas line plug (5) and connect the other end of the manometer to the plug opening and close the valve on the manometer. Start the engine and run it at low idle speed. Open the valve on the manometer. Gas pressure is correct when the pressure can support 51/2 inches (13.97 cm.) of water. Stop the engine, remove the manometer and install the plugs (3) and (5). Install the manometer on the other carburetor and repeat the above procedure.
LINE PRESSURE REGULATOR
1-Line pressure regulator. 2-Plug in manometer connection opening.
CARBURETOR (Impco)
3-Plug. 4-Carburetor. 5-Gas line plug. Turbocharged Engines Equipped with Ensign Carburetor Regulators: To check gas pressure between line pressure regulator (1) and carburetor regulator (6) connect one end of the manometer to the plug opening at (2) on the line pressure regulator and connect the other end of the manometer to the carburetor regulator plug opening at (7) and close the valve on the manometer. Start the engine and run it at low idle speed. Open the valve on the manometer. Gas pressure is correct when the pressure can support 7 to 10 inches (18 to 25 cm.) of water. Stop the engine, remove the manometer and install the plugs (2) and (7). Install the manometer on the other line pressure regulator and carburetor regulator and repeat the above procedure.
CARBURETOR REGULATOR (Ensign)
6-Carburetor regulator. 7-Plug in manometer opening. Naturally Aspirated Engines Equipped with Ensign Carburetor Regulators: To check gas pressure to the carburetor regulator on a naturally aspirated engine, connect one end of the manometer to the carburetor regulator plug opening at (7), and leave the other end of the manometer open to the atmosphere and close the valve on the manometer. Start the engine and run it at low idle speed. Open the valve on the manometer. Gas pressure to the carburetor regulator should support 7 to 10 inches (18 to 25 cm.) of water. Stop the engine, remove the manometer and install the plug (7).At the time of installation or whenever it is suspected that the line pressure regulator requires adjustment, see your Caterpillar dealer.Checking Throttle Valve Synchronization
(Engines Not Running)
Engines Equipped with Impco Carburetors:If the throttle valves are not opening simultaneously on both carburetors, the load will not be balanced between the two banks of the engine, and uneven running may result. The throttle valves may be checked and approximately synchronized in the following manner:1. Disconnect both linkages (1).
THROTTLE VALVE SYNCHRONIZATION
1-Governor linkage 2-Throttle stop screw. 3-Stop.2. Turn the low idle throttle stop screw (2) out until each throttle will close without allowing the screw to touch the stop (3).3. Adjust each low idle throttle-stop screw so it will just touch the stop with the throttle valve remaining closed.4. Move the governor control lever to the "off" position.5. Adjust the length of the governor to carburetor linkages so both connections can be made with the throttle valves completely closed and the governor fully retarded.6. Connect both linkages from the governor to the levers on the throttle valve shaft.For final adjustment see the topic, CHECKING THROTTLE VALVE SYNCHRONIZATION (Engine Running).Engines Equipped with Ensign Carburetor Regulators:If the throttle valves are not opening simultaneously on both carburetors, the load will not be balanced between the two banks of the engine, and uneven running may result. The throttle valves may be checked and approximately synchronized in the following manner:1. Disconnect both linkages (1) from the governor to levers on throttle valve shaft (5) by removing the clevis pin (2) in each linkage.2. Turn the low idle throttle stop screw (3) out until each throttle will close without allowing the screw to touch the stop.3. Adjust each low idle throttle-stop screw so it will just touch the stop with the throttle valve remaining closed.4. Move the governor control lever to the "off" position.
THROTTLE VALVE SYNCHRONIZATION
1-Linkage. 2-Clevis pin. 3-Low idle speed stop screw. 4-High idle speed stop screw. 5-Throttle valve shaft.5. The lever on the throttle valve shaft should be in the same relative angular position to the throttle plate on both carburetors. Adjust levers, if necessary, to obtain that condition.6. Adjust the length of the governor to carburetor linkages so both connections can be made with the throttle valves completely closed and the governor fully retarded.7. Connect both linkages from the governor to the levers on the throttle valve shaft.For final adjustment see the topic, CHECKING THROTTLE VALVE SYNCHRONIZATION (Engine Running).