| Symptom | Most likely causes | First checks |
|---|---|---|
| Engine runs but weld is weak | Wrong weld range, loose output lugs, feeder mismatch | Verify settings, studs, and lead integrity |
| Engine hunts under load | Fuel or governor issue, excessive auxiliary load | Remove external load and verify engine basics |
| Auxiliary power is normal but weld is not | Weld-output path issue | Focus on weld settings, studs, and clamp |
| Hard start or unstable run | Fuel, battery, or maintenance state | Verify battery and engine service basics |