| 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 or droops under load | Fuel delivery, regulator issue, excessive auxiliary load | Remove external load and verify fuel supply |
| Auxiliary power is normal but weld is not | Weld-output path or control issue | Focus on weld settings, studs, and leads |
| Hard start or unstable idle | LPG supply issue, battery, maintenance state | Verify fuel delivery, battery, and service basics |