This demonstration guide answers one field question about fatigue at the impeller hub after repeated shocks. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with dye or visual crack map at the hub. That reading separates fatigue at the impeller hub after repeated shocks from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the impeller as the primary path. If it is in spec, do not replace the impeller just to complete a parts list.
Repair the failed system
The usual correction is the impeller, installed to the documented spec for this complaint.
A demonstration shop records the finding so the next technician is not repeating a guess about fatigue at the impeller hub after repeated shocks.
Stop before you make it worse
Do not welding a crack without inspecting balance. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the impeller is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.