Generator output voltage is normal but frequency is low or high, causing equipment issues without a trip.

Safety: Adjustments should be made by trained personnel while observing rotating parts.

• Measure frequency: Use a frequency meter at the generator terminals to confirm deviation from rated Hz.
• Inspect linkage: Check the JCB engine governor arm, springs, and linkages for dirt, corrosion, or binding. Clean and lubricate as needed.
• Adjust speed: Using the governor speed adjustment screw, carefully set engine speed to achieve correct no‑load frequency. Lock the adjustment when done.
• Verify under load: Apply typical load and confirm frequency remains within tolerance. If not, governor components may need replacement.