This demonstration guide answers one field question about a lean surge when the deck hits dense turf. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with throttle-shaft play measured against the carburetor bore. That reading separates a lean surge when the deck hits dense turf from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the governor spring and throttle shaft as the primary path. If it is in spec, do not replace the governor spring and throttle shaft just to complete a parts list.
Repair the failed system
The usual correction is the governor spring and throttle shaft, 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 lean surge when the deck hits dense turf.
Stop before you make it worse
Do not enriching the mixture without inspecting governor linkage. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the governor spring and throttle shaft is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.