failure mode
FM-10: FM-10 BAR-LOCK OR CHAIN-TENSION KNOB WILL NOT TURN, ENGAGE, OR HOLD
FM-10 BAR-LOCK OR CHAIN-TENSION KNOB WILL NOT TURN, ENGAGE, OR HOLD
Diagnostic overview
FM-10 BAR-LOCK OR CHAIN-TENSION KNOB WILL NOT TURN, ENGAGE, OR HOLD
Likely Root Causes
- Knob was overtightened or cross-threaded
- Resin, chips, or dirt in the threads
- Tensioner tab is outside its slot
- Stripped knob, bolt, cover, or tensioner teeth
- Cracked sprocket cover
Quick Checks
- POST-REPAIR CHECK
Related symptoms
A tool-free knob is frozen, cross-threaded, spins without effect, will not clamp the bar, or cannot hold the set tension.
effect, will not clamp the bar, or cannot hold the set tension. 1. Remove the battery and do not use pliers or excessive force on either plastic knob. and cover clean, and inspect for cracks or stripping.
Included in the full manual
- root cause analysis
- tools needed
- step-by-step repair procedure
- diagrams
- exploded views
- post-repair checks
Public pages show a preview only. Purchase the full manual to download complete repair steps, diagrams, and verification procedures.