This demonstration guide answers one field question about uneven cutter length or a worn bar rail. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with cutter length compared across left and right teeth. That reading separates uneven cutter length or a worn bar rail from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the chain and bar as the primary path. If it is in spec, do not replace the chain and bar just to complete a parts list.
Repair the failed system
The usual correction is the chain and bar, installed to the documented spec for this complaint.
A demonstration shop records the finding so the next technician is not repeating a guess about uneven cutter length or a worn bar rail.
Stop before you make it worse
Do not forcing the saw to "steer" the cut back to center. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the chain and bar is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.