Grinding means metal-on-metal contact. Immediate causes: no bar oil, incorrect chain tension, or damaged drive components.
- STOP USING IT. Further use will destroy the bar and chain.
- Check oil level immediately. Inspect the oil-inspection window. Fill if below minimum mark.
- Check chain tension. With brake engaged, the chain should be snug on the guide bar but still pull freely by hand. Adjust with the quick chain-tension adjust knob.
- Inspect the sprocket in the guide bar tip and the drive sprocket on the power head. Look for broken, worn, or missing teeth. A worn sprocket won't mesh with the chain drive links correctly.
- Verify chain direction and model. Arrows must match. Use only 91PX062X, 90PX056X, or 90PX052X chains.
IF THAT DIDN'T WORK: The guide bar groove may be pinched or the chain drive links are damaged. Visually inspect the entire loop of the chain for damaged, cracked, or bent links. Replace both the chain and bar if either is visibly worn or grooved.
HEADS UP: This is a sign of neglect. Always check chain tension and oil level before every use. A sharp, well-lubricated, properly tensioned chain runs smoothly and quietly.