Generator attempts to start, fires briefly, then stalls; control panel shows E03.

Safety first: Turn the generator OFF, disconnect the battery, and keep hands clear of moving parts. Do not run the unit with covers removed unless necessary for testing.

• Inspect throttle and governor linkage: Remove the access panel and locate the throttle plate and governor arm on the carburetor or throttle body. Move the linkage by hand; it should move smoothly and return via the governor spring. Clean any dirt or corrosion and lubricate pivot points lightly.
• Check governor spring: Ensure the governor spring is intact and properly hooked between the governor arm and speed control lever. Replace if stretched or broken.
• Inspect engine speed sensor: Many All Power America standby generators use a magnetic pickup near the flywheel or a sensor on the ignition coil. Check the sensor gap (refer to service manual, typically 0.5–1.0 mm) and ensure the sensor is clean and firmly mounted. Replace the speed sensor if its wiring is damaged or if resistance is out of spec.
• Check wiring to controller: Trace the RPM sensor wires back to the control board. Repair any chafed wires and clean corroded connectors.
• Test run: Reconnect the battery, start in MANUAL, and observe if E03 reappears. If overspeed persists, the control board's governor output or RPM sensing circuit may be faulty and require replacement.