Cummins/Onan ENGINE Generator Set

⚠ Fuel is highly flammable and may cause severe personal injury and property damage. Do not allow cigarettes, flame, pilot lights, arcing switches or equipment in area or areas sharing ventilation.

Tools: exhaust gas analyzer (for emission sensitive areas)

1. Start the engine and let the set warm up under a partial load (at least 1/4 rated load). Start with natural gas if dual fuel.
2. Connect full rated load and turn the power adjust valve two turns counterclockwise.
3. Slowly turn the manual fuel valve clockwise (lean) until the engine begins to lose speed.
4. Slowly turn counterclockwise (rich) until the engine carries full load smoothly.
5. If dual fuel, switch to LPG by closing the manual shutoff valve in the natural gas supply line.
6. Reconnect full rated load and turn the LPG flow adjustment valve clockwise until the engine begins to lose speed.
7. Slowly turn it back counterclockwise until the engine carries full load smoothly.

⚠ Do not clean filter housing while still installed. Loose dirt entering intake could damage carburetor or engine.

Tools: low pressure air source (30 psi)

1. Remove wing nut in center of filter cover; remove cover and filter.
2. Tap filter on a flat surface to remove dirt.
3. Place a light source inside filter and inspect for air passage.
4. If necessary, apply a low pressure air source (30 psi) to the inside of filter to remove dirt.
5. Inspect interior housing; vacuum clean if dirty or remove housing and wipe clean.

⚠ Some coolant is toxic. Follow local environmental regulations for disposal.

⚠ 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 coolant is drained, place the end of a water hose into the radiator filler and turn on water supply.
5. Regulate flow until inflow equals outflow; 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; refill with recommended coolant.

⚠ Contact with used engine oil can cause cancer or reproductive toxicity. Do not contact oil or breathe vapors.

⚠ Hot crankcase oil can cause burns if spilled or splashed on skin. Keep fingers and hands clear when removing the oil drain plug and wear protective clothing.

Tools: drain pan

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

⚠ Do not add cold coolant to a hot engine. Engine castings can be damaged. Allow the engine to cool to below 120 F (50 C) before adding coolant.

⚠ To prevent severe scalding, let engine cool down before removing coolant pressure cap.

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

⚠ Used oil and filters must be disposed of properly to avoid environmental damage and clean-up liability.

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, then turn an additional 1/2 to 3/4 turn. Do not overtighten.
5. With oil in crankcase, start engine and check for leaks around filter element.
6. Retighten only as much as necessary to eliminate leaks but do not overtighten.

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

Tools: battery hydrometer

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 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.

⚠ Carbon Fouled indicates overly rich mixture; Oil Fouled indicates high oil consumption; Burned indicates excessive engine temperature.

Tools: spark plug gap gauge

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 before installing.
5. Lightly lubricate spark plug threads with high temp anti-seize compound (not required for standby power genset spark plugs).

⚠ The belt idler is under tension. Do not allow your hands to get between the belt and pulley. Personal injury will result.

Tools: 1/2 inch male square ratchet or breaker bar

1. Disconnect the negative (-) cable from the battery to prevent accidental starting.
2. Remove fan guard (between engine and radiator) to gain access to the serpentine belt.
3. Insert a 1/2 inch male square ratchet or breaker bar into tensioner arm.
4. With handle extended to the right of the tensioner arm, slowly lift up until spring tension is relieved.
5. Remove serpentine belt.

⚠ The belt idler is under tension. Do not allow your hands to get between the belt and pulley. Personal injury can result.

Tools: 1/2 inch male square ratchet or breaker bar

1. Slip new serpentine belt onto all pulleys except for the water pump/fan drive pulley.
2. Insert a 1/2 inch male square ratchet or breaker bar into tensioner arm.
3. Lift up until spring tension is relieved sufficiently to position the belt over the water pump/fan drive pulley; slowly release spring tension onto belt.
4. Install fan guard.
5. Connect the negative (-) cable to the battery.
6. Start genset and visually check belt for proper alignment with engine running.