This demonstration guide answers one field question about oil that will not flow in cold wood or flings off in heat. Measurements come before parts, and the notes are not a generic equipment FAQ.
Diagnose before replacing parts
Start with oil flow on a test card at ambient temperature. That reading separates oil that will not flow in cold wood or flings off in heat from adjacent faults that share the same complaint.
If the measurement is out of spec, treat the bar oil as the primary path. If it is in spec, do not replace the bar oil just to complete a parts list.
Repair the failed system
The usual correction is the bar oil, installed to the documented spec for this complaint.
A demonstration shop records the finding so the next technician is not repeating a guess about oil that will not flow in cold wood or flings off in heat.
Stop before you make it worse
Do not using motor oil as a permanent bar-oil substitute. That shortcut hides the original measurement and creates a second failure.
If the machine still fails after the bar oil is corrected, convert the visit to a broader diagnosis rather than stacking parts.
Written and published by Ridgeline Small Engine.