The part(s) or condition(s) listed below for the symptom Chainsaw chain won't stop turning are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The clutch pads engage the clutch drum to rotate the chain. When the engine slows, the return springs retract the pads to disengage the chain. If the springs are broken, the clutch pads won’t retract, preventing the chain from stopping. If the clutch pads are sticking, the clutch drum will stay engaged and continue to turn. If the springs are broken or the clutch pads are sticking, replace the clutch assembly.