Generator starts but quickly shuts down and displays OVERSPEED fault; may sound unusually loud or high-pitched just before shutdown.

Safety first: Turn the generator to OFF and open the main breaker to isolate the generator from the home. Allow the engine to cool before inspection.

• Inspect throttle linkage: Remove the top cover and visually inspect the throttle linkage and return spring on the Centurion engine. Ensure the linkage moves freely and is not obstructed by debris or rodent nests.
• Check for binding: Manually move the throttle lever (engine off) to confirm smooth travel. Lubricate pivot points lightly with a non-gumming lubricant if dry or sticking.
• Inspect speed sensor wiring: Locate the magnetic pickup / engine speed sensor near the flywheel or crankshaft. Check the harness for chafing, loose connectors, or corrosion at the plug.
• Reset controller: Clear the fault by turning the controller OFF for 30 seconds, then back to AUTO. Run a manual test. If OVERSPEED reappears immediately, do not continue to start the unit.

When to call a technician: Overspeed conditions can damage the alternator and engine. A technician should verify RPM with a tachometer, test the speed sensor, and adjust or replace the electronic governor or control board as needed.