GM / Onan GM 5.0 L Onan Modified GM V-8 Engine

Tools: InPower Service Tool

1. Press the button next to the arrow symbol until the + and - symbols are displayed.
2. If necessary, press the button next to the symbols to move to the numeric character to change.
3. Press + to increase the value or select parameter; press - to decrease or select parameter.
4. Press the arrow symbol to save changes (cursor on last numeric character when adjusting values).

⚠ Ensure that the equipment is stable before installation of the vibration isolator.

1. Place the vibration isolator under the support point of the equipment, ensure load is uniformly distributed over the top plate.
2. With the 6 mm spacer in position, tighten the positioning nut.
3. Turn the adjusting bolt of the spring counter-clockwise to load the spring.
4. Load all the FSR at the same time to ensure the total load is uniformly spread.
5. Continue until the spring load equals the load of the equipment.
6. When equilibrium point is reached, the 6 mm spacer can be removed from the FSR mount.

Tools: Battery hydrometer

1. Use a battery hydrometer to check the specific gravity of the electrolyte in each battery cell.
2. Hold the hydrometer vertical and take the reading.
3. Correct the reading by adding four gravity points (0.004) for every ten degrees the electrolyte temperature is above 80 deg F (27 deg C).
4. A fully charged battery will have a corrected specific gravity of 1.260.
5. Charge the battery if the reading is below 1.215.

⚠ Electrolyte is a dilute sulfuric acid that is harmful to the skin and eyes. Wear goggles and protective rubber gloves and apron.

1. Keep the batteries clean by wiping them with a damp cloth whenever dirt appears excessive.
2. If corrosion is present around the terminal connections, remove battery cables.
3. Wash the terminals with a solution consisting of 1/4 pound of baking soda added to 1 quart of water.
4. Be sure the vent plugs are tight to prevent cleaning solution from entering the cells.
5. After cleaning, flush the outside of the battery and surrounding areas with clean water.
6. Coat the terminals with a light application of petroleum jelly or non-conductive grease to retard corrosion.

⚠ The heater element will burn out if engine coolant is removed with heater connected to power source.

1. Disconnect engine coolant heater from power source (if equipped).
2. Allow the engine to cool and then remove radiator pressure cap.
3. Open the radiator drain cock and remove the water drain plugs (one on each side of engine).
4. When the coolant is drained, place the end of a water hose into the radiator filler and turn on water supply.
5. Regulate the flow of water until it equals the outflow from drain openings; continue flushing until outflow is clear of rust sediment.
6. If equipped with engine coolant heater, drain coolant by removing hose and clamp from bottom of heater.
7. Replace the water drain plugs and close the radiator drain cock when flushing is complete.
8. Refill the cooling system with the recommended coolant.

⚠ Hot crankcase oil can cause burns if it is spilled or splashed on skin.

⚠ Contact with used engine oil can cause cancer or reproductive toxicity.

1. Run engine until thoroughly warm before draining oil.
2. Stop the set, place a pan under the drain outlet.
3. Remove the oil drain plug or open the drain valve.
4. After the oil is completely drained, replace the drain plug or close the drain valve.
5. Refill with oil of the correct API viscosity grade for the temperature conditions.

⚠ Do not add cold coolant to a hot engine. Allow the engine to cool to below 120 deg F (50 deg C) before adding coolant.

1. Check that all drain cocks are closed and all hose clamps secure.
2. Open bleeder valve.
3. Remove the radiator pressure cap and slowly fill the cooling system with the recommended coolant.
4. When the coolant begins to flow from the engine bleeder valve, close the valve and continue filling the radiator.
5. When the engine is first started, remove the pressure cap and monitor the coolant level.
6. As trapped air is expelled, add coolant; replace the pressure cap when the coolant level is stable.

1. Spin off oil filter and discard it in accordance with local environmental regulations.
2. Thoroughly clean filter mounting surface.
3. Apply a thin film of oil to filter gasket and install new element.
4. Spin element on by hand until gasket just touches mounting pad and then turn an additional 1/2 to 3/4 turn.
5. Fill the oil filter with clean lubricating oil by pouring oil into the center hole of the filter.
6. With oil in crankcase, start engine and check for leaks around filter element.
7. Retighten only as much as necessary to eliminate leaks but do not overtighten.

1. Exercise the set as described in the operation section until the engine is up to operating temperature.
2. Shut down the engine.
3. Turn off and disconnect battery charger (if equipped).
4. Disconnect the battery (negative cable first) and store in a cool, dry place; connect to charger every 30 days.
5. Drain the engine oil while still warm and refill with new oil recommended for set; attach a tag indicating type of oil used.
6. Remove the spark plugs and pour two ounces of rust preventative oil into each spark plug opening; crank the set for five seconds and replace the spark plugs.
7. Disconnect engine coolant heater from power source (if equipped).
8. Drain the cooling system including the engine block.
9. Remove the air cleaner and seal off the carburetor air inlet opening and the PVC hose.
10. Plug the exhaust outlets to prevent entrance of moisture, bugs, dirt, etc.
11. Clean and wipe entire unit; coat parts susceptible to rust with a light coat of oil; cover entire set loosely after engine has cooled down.

1. Remove protective cover.
2. Remove exhaust plugs, seal from carburetor and PVC hose and replace air cleaner.
3. Check oil dipstick to make sure crankcase is full.
4. Refill cooling system.
5. Reconnect the battery (positive cable first) and check specific gravity.
6. Connect the battery charger (if applicable).
7. Connect engine coolant heater to power supply (if applicable).
8. Remove all loads before starting set.
9. Start set and apply load of at least 50% of nameplate rating.
10. Check all gauges for normal readings. Set is now ready for service.

1. Remove the spark plugs and inspect for damaged or cracked insulators, worn electrodes, or excessive carbon deposits.
2. Replace the spark plug if any of these conditions are noted.
3. Clean those plugs that can be reused and regap to the amount specified in the Specifications section.
4. Clean all dirt and grit away from the spark plug seats.
5. Lightly lubricate spark plug threads with high temp anti-seize compound.

⚠ Enabling Idle Start will cause the generator set to run in idle mode until Idle Start is disabled. A warning is displayed if generator set is left in idle more than 10 minutes. Long periods of engine idling can eventually affect engine performance and may void engine warranty.

1. Press the button next to the > symbol in the display until the + and - symbols are displayed.
2. If necessary, press the button next to the symbols to move to the numeric character you wish to change.
3. Press the button next to the + symbol to increase the value; press the button next to the - symbol to decrease the value.
4. After adjusting values, press the > symbol to save the changes (cursor must be on the last numeric character).
5. If the Home button or Previous Main Menu button is pressed before the > symbol, the changes are not saved.