Generator starts and then shuts down with 'Overspeed' displayed; engine RPM is detected above normal operating range.

Safety first: Turn the generator OFF, open the main breaker, and disconnect battery negative. Allow moving parts to stop completely.

Steps:

• Inspect throttle linkage: Remove the enclosure panel and visually inspect the throttle plate, governor arm, and linkage. Clean any dirt or corrosion and ensure the linkage moves freely and returns to idle by spring tension.
• Check for binding: Manually move the throttle lever at the carburetor or throttle body. If it sticks, lubricate pivot points lightly and free any obstructions.
• Inspect RPM sensor: Locate the engine speed sensor (often near the flywheel or crankshaft). Check for loose mounting, damaged wiring, or metal debris on the sensor tip. Clean and reseat the connector.
• Controller reset: Reconnect the battery, clear the Overspeed alarm, and run a manual test. Monitor frequency (Hz) at the output with a meter if available.
• If overspeed persists: The electronic governor module or controller may be faulty. This requires specialized tools and should be handled by an authorized Honeywell/Generac technician.