Cummins/Onan Performer P224 Engine

⚠ Gaseous fuels are flammable and explosive. Keep all ignition sources away. High gas supply pressure can cause gas leaks.

Tools: Manometer (at least 14 inches / 350 mm WC)

1. Close the gas supply shutoff valve.
2. Remove the 1/8 inch pipe plug from the regulator test port and connect a manometer (scale range at least 14 inches WC).
3. Open the gas shutoff valve and try starting the genset.
4. While genset runs at no load, adjust the gas supply pressure regulator to obtain 11 inches (279 mm) WC.
5. If genset will not start, jumper the fuel solenoid to the battery cable connections so it stays open, then check and adjust pressure.
6. Check gas supply pressure under full load; low pressure may indicate undersized supply piping.
7. Disconnect any jumpers and thread in and tighten the pressure test port plug.

1. Unsnap the yoke from the ball joint on the throttle lever. Make sure ball joint is mounted in lower hole of throttle lever.
2. Loosen the yoke locknut.
3. While holding the throttle lever against the throttle stop screw, turn the yoke in or out to align the hole in the yoke to the end of the ball stud.
4. Then turn the yoke two full turns to shorten the linkage and tighten the locknut.
5. Make sure yoke is perpendicular to the face of the throttle lever, then install yoke onto ball joint.

⚠ Automatic startup of the genset while performing maintenance can cause severe personal injury or death. Push the control switch to Off and disconnect the negative (-) battery cable.

Tools: 7/16 inch socket, 5/8 inch socket, 9/16 inch tappet wrench, 7/16 inch tappet wrench, Feeler gauge

1. Remove the roof panel.
2. Remove the intake manifold to access the valve tappets. Air cleaner housing may stay on carburetor.
3. Remove the air intake screen from the engine divider panel.
4. Remove the valve covers (use 7/16 inch socket).
5. Remove the spark plugs (use 5/8 inch socket) to ease turning the engine.
6. Rotate crankshaft clockwise with a 5/8 inch socket on the flywheel capscrew. When one cylinder's valve begins to move, adjust the opposite cylinder.
7. Measure clearance with feeler gauge between valve stem and tappet.
8. Use a 9/16 inch tappet wrench to hold the tappet; turn the 7/16 inch adjusting screw as needed. Screw is self-locking.
9. For the left cylinder, turn engine one revolution until TC marks line up, then repeat.
10. Replace all parts, use new gaskets, and torque all screws according to Thread Torques.

⚠ Do not reverse battery leads. Do not allow engine to run without being connected to the alternator.

Tools: Volt-ohmmeter

1. Check battery voltage with unit not running. If not within 12 to 13 VDC, charge battery.
2. With engine running, check battery terminal voltage (regulator output). Should be 13.6 to 14.7 VDC.
3. If greater than specified, replace regulator-rectifier assembly; if less, check wires, connections and fuses.
4. Disconnect both AC stator leads and test AC voltage at stator leads with engine running. Should be 57 VAC.
5. Use the Rx1 scale to check stator for open or ground. Stator winding resistance should be 0.01 to 0.19 Ohms.

Tools: Cylinder compression tester

1. Start the genset and let it warm up.
2. Stop the genset and remove and inspect the spark plugs.
3. Insert the compression gauge nozzle into one spark plug hole, hold the throttle open and crank the engine. Note the pressure.
4. Repeat the test on the other cylinder.
5. Service the engine if pressures do not meet Specifications (minimum 75 psi / 517 kPa).

⚠ Many troubleshooting procedures present hazards that can result in severe personal injury or death. Only qualified service personnel should perform service.

Tools: Digital ohmmeter, Megger or insulation resistance meter

1. Test field flash voltage at brush holder terminals with engine cranking; check for 12 VDC.
2. If not present, disconnect F1 and F2 leads and check for 12 VDC while cranking engine.
3. Test rotor grounds between each slip ring and rotor shaft (Megger at 500 VDC or more). Reading should be 100,000 ohms or greater.
4. Test rotor for open/shorted windings between F1 and F2 leads. Resistance should be 25.47 ohms +/- 10%.
5. Isolate stator windings and test for opens and grounds between T1-T2, T3-T4 and Q1-Q2.
6. Resistance values: T1-T2 0.095 ohms, T3-T4 0.095 ohms, Q1-Q2 1.185 ohms (+/- 5%).

1. Set the genset control to the Off position.
2. Remove the through-bolt and cover.
3. Reassemble the air filter with a new air filter element and wrapper. Do not oil the filter or wrapper.
4. Do not over-tighten the through bolt.

⚠ Batteries give off explosive gases. Do not smoke near batteries. Battery electrolyte can cause severe eye damage and skin burns.

Tools: Battery hydrometer, Terminal puller

1. Keep the battery case clean and dry.
2. Make certain battery cable connections are clean and tight. Use a terminal puller to remove cables.
3. Always remove the negative (-) cable first and connect it last to reduce arcing risk.
4. Remove corrosion from terminals with an ammonia solution or 1/4 lb baking soda in 1 quart water. Keep vent plugs tight.
5. For non-maintenance-free batteries, add distilled water to the split-level marker; add water, not electrolyte.
6. Use a hydrometer to check specific gravity. Charge if less than 1.215; stop charging at 1.260 at approximately 80 deg F (27 deg C).

⚠ State and federal agencies have determined that contact with used engine oil can cause cancer or reproductive toxicity. Use rubber gloves and wash exposed skin.

Tools: Oil filter wrench, Oil drain pan

1. Place a pan under the oil drain hose. Run engine until warm, then shut it off.
2. Remove the oil fill cap, remove the hose plug, open the oil drain valve, and drain all oil.
3. Close the oil drain valve and replace the hose plug.
4. Spin off the oil filter canister and catch the oil. Discard filter per local regulations.
5. Wipe the filter mounting surface clean; make sure old gasket is not stuck.
6. Ensure gasket is in place on new filter and apply a thin film of oil to it.
7. Spin on new filter by hand until gasket touches pad, then 1/2 to 3/4 turn more. Do not over-tighten.
8. Refill with oil per Engine Oil Recommendations and Specifications. Check oil level.
9. Secure the oil fill cap with a 1/4 turn. Return genset control to Auto when finished.

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

1. Set the genset control to the Off position.
2. Remove the oil fill cap/dipstick, wipe it clean, screw the cap back on, then remove it again.
3. Add oil as necessary until the full mark is reached. Do not fill above the full mark.
4. Secure the oil fill cap by turning 1/4 turn to prevent oil leakage.

⚠ This unit can start automatically. Disconnect the negative (-) cable from the battery. Do not operate the genset without the housing panels secured in place.

1. Close the fuel supply shutoff valve. If genset can be started, run it until it runs out of fuel.
2. Press the control switch to Stop.
3. Remove the front access panel.
4. Disconnect the negative (-) battery cable from the battery to prevent accidental starting.
5. Open side doors by lifting handle up and out, turning counter-clockwise, and lifting out.
6. Remove the two side doors, then the roof panel.
7. Remove the appropriate end panel to access the control assembly, alternator or engine.
8. Reassembly is the reverse. Wait to tighten screws until all panels and screws are in place.

Tools: Spark plug socket, Torque wrench, Spark plug gap gauge

1. Set the genset control to the Off position.
2. Thread the spark plug in by hand until it seats to prevent crossthreading.
3. If reusing, turn it with a wrench an additional 1/4 turn. If new, turn an additional 3/8 to 1/2 turn.
4. If using a torque wrench, tighten the spark plug to 8 lb-ft (10 N-m).