VALVE 7J8307 - Caterpillar

Incorrect compensation adjustments can result from the following conditions: high overspeeds after load changes, low speeds after load changes and slow return to normal speed. The governor may appear to be operating normally at no load.After the temperature of the engine and the oil in the governor have reached normal operating values, make adjustments with the engine running at no load conditions.
Illustration 1 g00868768
UG8 lever type governor (typical example)
(1) Compensation pointer
(2) Nut
(3) Plug
Loosen nut (2) that holds compensation pointer (1). Rotate the pointer to the uppermost position. Tighten nut (2).
Remove plug (3) from the base of the governor in order to get access to the needle valve.
Use a screwdriver in order to turn the needle valve. Turn the needle valve in a counterclockwise direction to the open position. Ensure that the screwdriver engages with the shallow slot of the compensation needle valve. Be sure that the screwdriver does not engage in the deep slot that is at a right angle to the shallow slot.
Allow the engine to surge for approximately 30 seconds in order to help remove air from the governor oil passages.
Loosen nut (2) that holds compensation pointer (1). Rotate compensation pointer (1) to the original position. Tighten nut (2).
Determine the number of turns that are required in order to open the needle valve. Close the valve completely and make a note of the number of turns needed in order to close the valve.
Turn the needle valve in a clockwise direction until the engine's speed surge stops.
When the engine's speed surge stops, open the needle valve. Note: If the following conditions are met, then governor adjustment is correct. There is no engine's speed surge. The needle valve is 1/2 to 3/4 of a turn toward the open position.
Move the governor linkage in order to change the engine speed. Install plug (3) in the base. If the needle valve is more than 3/4 of a turn open, proceed with the following steps.
Loosen nut (2). Move compensation pointer (1) up two marks on the pointer scale.
Turn the needle valve in a counterclockwise direction. Rotate 3 to 5 turns.
Allow the engine to surge for approximately 30 seconds in order to help remove air from the governor oil passages.
Turn the needle valve in a clockwise direction until the engine's speed surge stops.
Determine the number of turns that are required in order to open the needle valve. Close the valve completely and make a note of the number of turns needed in order to close the valve.
Turn the needle valve to the previous position. Refer to Step 13.
Move the governor linkage in order to change the engine speed. Note: If the following conditions are met, then governor adjustment is correct. There is no speed surge. The needle valve is 1/2 to 3/4 of a turn toward the open position. If the needle valve is more than 3/4 of a turn open, repeat Steps 10 through 16.Note: A needle valve that is opened less than 1/2 turn will cause a slow return of the