This demonstration guide answers one field question about a chain that was tensioned cold and then sags. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with drive-link hang at operating temperature. That reading separates a chain that was tensioned cold and then sags from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the tensioner pin as the primary path. If it is in spec, do not replace the tensioner pin just to complete a parts list.
Repair the failed system
The usual correction is the tensioner pin, installed to the documented spec for this complaint.
A demonstration shop records the finding so the next technician is not repeating a guess about a chain that was tensioned cold and then sags.
Stop before you make it worse
Do not tensioning so tight the chain will not drag by hand cold. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the tensioner pin is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.