Cummins/Onan 2.5EGHAA Engine

Tools: feeler gauge, wrenches

1. Adjust only when engine is at ambient temperature.
2. Rotate engine until piston is at top dead center and both valves closed.
3. Check clearance between valve stem top and rocker arm with feeler gauge.
4. Loosen locking nut and turn adjusting nut to obtain correct clearance.
5. Tighten locking nut and recheck clearance.
6. Check rocker arm bolts have not loosened.

⚠ Disconnect battery before servicing to prevent accidental starting.

Tools: jumper leads

1. Connect jumper lead between battery positive (+) terminal and solenoid S terminal.
2. Momentarily connect jumper between battery negative (-) and solenoid body.
3. Solenoid contacts should close; replace solenoid if it does not activate.

⚠ Failure to adequately wring out excess oil may cause a drop in engine power due to restriction of inlet air.

1. Remove the outer cover by rotating the quarter-turn fastener counterclockwise to its vertical position; lift off the cover.
2. Remove and wash the foam wrapper in water and detergent; squeeze it dry like a sponge, rinse and allow to dry.
3. Coat the wrapper evenly with one tablespoon (14 grams) of SAE 30 engine oil; knead in and wring out excess oil.
4. Re-install the foam wrapper over the paper element by stretching it over the inner cover.
5. For element replacement, close the choke plate; remove the mounting nut, inner cover and element; wipe the base clean.
6. Install the new paper element and secure with the inner cover and nut; tighten the nut 1-1/2 turns after seating.

⚠ Ignition of explosive battery gases can cause severe personal injury. Do not smoke or allow any flame, spark or other ignition source near the battery.

⚠ Battery electrolyte can cause severe eye damage and skin burns. Wear goggles, rubber gloves and a protective apron.

Tools: Battery hydrometer, Battery puller tool

1. Keep the battery case clean and dry; wipe with a damp cloth when dirt accumulates.
2. Make certain the battery cable connections are clean and tight; use a battery puller tool to remove cables.
3. Identify cables as positive (+) or negative (-) before connecting. Connect the negative (-) cable last.
4. Apply a light coating of petroleum jelly or non-conductive grease to battery connections to retard corrosion.
5. Maintain the electrolyte level by adding distilled water as needed to reach the split-level marker.
6. Use a battery hydrometer to check specific gravity of each cell. Charge if below 1.215; stop charging at 1.260 at about 80 F (27 C).

⚠ Fuel presents fire or explosion hazard; keep ABC extinguisher nearby.

1. Close fuel supply valve; run set until it runs out of fuel; let cool.
2. Remove fuel line from shutoff valve and collect fuel in a container.
3. Unscrew sediment bowl from fuel supply valve and clean it.
4. Remove screen and clean dirt and particulate off the screen.
5. Reinstall screen and sediment bowl; attach fuel line securely.

⚠ Fuel presents the hazard of fire or explosion. Do not permit any flame, spark, pilot light, cigarette, or other ignition source near the fuel system.

1. Close the fuel supply valve and let the set run until it runs out of fuel; let it cool down.
2. Remove the fuel line from the fuel shutoff valve and collect the fuel in a suitable container.
3. Unscrew the sediment bowl from the fuel supply valve and clean it.
4. Remove the screen and clean any dirt and particulate off the screen.
5. Reinstall the screen and sediment bowl. Attach the fuel line securely to the fuel shutoff valve.

⚠ Exhaust gas hazard; do not operate with any exhaust leaks.

Tools: wrenches

1. Allow set to cool before servicing.
2. Remove heat shield covering exhaust pipe and engine.
3. Remove mounting nuts securing muffler flange to engine.
4. Remove screws securing muffler to support bracket and generator flange; remove exhaust gasket.
5. Install new exhaust gasket and muffler; tighten hardware to specified torque.

⚠ A hot muffler can cause severe burns.

⚠ Most part cleaning solvents are flammable; work in a well ventilated area and keep an ABC fire extinguisher nearby.

Tools: Wire brush, Commercial solvent

1. Allow the generator set to cool down before servicing the muffler.
2. Inspect the muffler for corrosion and physical defects.
3. Operate the set and check for exhaust leaks and noisy operation; replace a noisy or defective muffler.
4. Remove the spark arrester screen and inspect for damage; replace if defective.
5. Clean by lightly tapping the screen and cleaning deposits with a wire brush; use commercial solvent if necessary.
6. Allow screen to dry, then reassemble and attach securely.

⚠ Accidental starting of the engine can result in severe personal injury or death. Disconnect the spark plug and battery negative cable before changing oil.

⚠ Crankcase pressure can blow hot engine oil out the fill opening causing severe burns. Stop the genset before removing the oil fill cap.

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

1. Run the engine until warm. Stop it and disconnect the spark plug and, if equipped, the battery negative (-) cable. Make sure the set is level.
2. Remove the oil fill cap.
3. Place a pan under the oil drain opening and remove the oil drain plug. (5.0 kW and above: spin off the oil filter canister.)
4. Reinstall the drain plug securely after the oil has drained completely.
5. Wipe the filter mounting surface; be sure the gasket is in place and coat it with a thin film of oil.
6. Spin on the new filter by hand until the gasket touches the pad, then turn an additional 1/2 to 3/4 turn. Do not overtighten.
7. Refill with API Class SG or SH oil of the correct viscosity; see Specifications for oil capacity.
8. Reconnect the spark plug and battery. Start the engine and check for oil leaks around the drain plug and filter.

⚠ Hot oil can cause severe burns.

⚠ Battery electrolyte can cause severe eye damage and burns to the skin.

⚠ Batteries present the hazard of explosion.

1. Add a fuel preservative and stabilizer such as OnaFresh to the fuel supply; run at 50 percent load for 30 minutes.
2. Disconnect the load; turn the fuel supply valve off and remove the air filter.
3. As the set runs out of fuel, squirt fogger such as OnaGard into the carburetor intake, then reassemble the air filter.
4. When the set stops, remove the spark plug and squirt one tablespoon (about 30 ml) clean engine oil into the spark plug hole; turn the engine over several revolutions; replace the plug.
5. Drain the oil base while still warm; refill the crankcase and attach a tag indicating oil viscosity used.
6. Electric start models: disconnect battery negative (-) cable first; store battery in a cool dry place and connect to a charger every 30 days.
7. Cover the generator set and store in a dry protected area.

⚠ Shut the fuel valve and handle the fuel tank carefully to prevent fuel leakage when raising the fuel tank.

Tools: Wire brush, Wrench, Torque wrench

1. Remove the spark plug and clean carbon and other deposits off with a wire brush.
2. Inspect and measure the plug gap. Replace the plug if it is discolored or badly fouled.
3. Thread the spark plug in by hand until it seats to prevent cross-threading.
4. If reusing the spark plug, turn it with a wrench an additional 1/4 turn.
5. If the spark plug is new, turn it an additional 3/8 to 1/2 turn; or torque to 20 lbs-ft (26 N-m).
6. If needed, the fuel tank can be raised for easier service access after reducing fuel level and closing the fuel shutoff valve.

⚠ Continuous overloading can cause high operating temperatures that could damage the set. Keep the load within the nameplate rating.

⚠ Electrical shock can cause severe personal injury or death. Cord and plug equipment must have a ground terminal.

1. Note the rated output of the generator set from the nameplate or Specifications section.
2. Check the load rating of each load; total wattage must not exceed the genset rated output.
3. If a motor load and another load are close to rated output, start the motor load first and let it reach normal speed.
4. Connect the AC loads to the receptacle(s) on the control panel.
5. Make sure the cord and plug connector have ground terminals.