BENCH GP 4C9540 - Caterpillar

The engine can overspeed due to improper reassembly or adjustment, which could result in personal injury, or loss of life, and/or property damage.
Be prepared to stop the engine by activating the emergency air shutoff or by manually closing the air inlets.
8. Turn the load limit knob on the EGB29P Governor/Actuator so the pointer is between 5 and 6. This will limit maximum power to about half of rated power.9. For start-up, turn the speed adjust potentiometer that has been connected to terminals 23 and 24 of the 2301A Governor to minimum speed. Crank the engine and slowly turn the speed adjust potentiometer to increase speed until the engine starts.
Be ready to control the engine shutoff manually if there is no oil pressure or if oil pressure is too low. Damage to the engine will be the result if the engine continues to run without the correct oil pressure.
10. Increase engine speed by turning the speed adjust potentiometer to increase speed to approximately 500 rpm.11. Adjust the speed control knob on the EGB29P Governor/Actuator to decrease speed. It may require several counterclockwise (CCW) turns before the engine speed begins to drop. Set engine speed to 400 rpm.12. You are now controlling engine speed with the mechanical governor (ballhead). Open the governor needle valve by turning it CCW until the engine speed hunts. After 20 to 30 seconds turn the needle valve CW just until the speed hunt stops. Do not close needle valve all the way! Turning it CW too far will result in slow engine response.13. Check actuator oil level and add oil to reach mark on sight glass.14. Turn the speed adjust potentiometer that is connected to terminals 23 and 24 on 2301A Governor in the increase speed direction as far as it will go. Be sure that the label over the maximum speed setting has not been removed or tampered with.15. Adjust the speed control knob on the EGB29P Governor/Actuator to reach rated speed. Disturb engine speed by bumping shutoff or turning the fuel off and on quickly with the normal shutdown switch. Observe response and adjust the needle valve to get stability with good response. Needle valve setting should be 1/8 to 1/2 turn open. Do not close needle valve all the way.16. Turn the load limit knob on the EGB29P Governor/Actuator to maximum fuel.17. Adjust the speed droop knob on the EGB29P Governor/Actuator to obtain the desired speed droop. Turn CW to increase droop. Load engine and measure speed at full load. (Be sure that you are not against rack stop.)18. Adjust the speed control knob on the EGB29P Governor/Actuator so that the minimum speed (you must take droop into account) is 15 rpm above the desired engine speed when running under the control of 2301A electric governor. If the mechanical governor speed setting is too close to the electric governor speed setting, the speed will not be stable as the two governors fight for control.Example:
Electric governor setting - 900 rpm at zero droop
Mechanical