This demonstration guide answers one field question about score marks that will not hold a ring seal. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with wall score depth. That reading separates score marks that will not hold a ring seal from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the piston and cylinder as the primary path. If it is in spec, do not replace the piston and cylinder just to complete a parts list.
Repair the failed system
The usual correction is the piston and cylinder, installed to the documented spec for this complaint.
A demonstration shop records the finding so the next technician is not repeating a guess about score marks that will not hold a ring seal.
Stop before you make it worse
Do not honing past the documented limit to "clean it up". That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the piston and cylinder is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.