Black smoke from exhaust under load, generator frequency and voltage sagging

Safety first: Avoid prolonged operation with heavy black smoke; it can damage the engine.

• Reduce load: Immediately reduce generator load to within nameplate rating.
• Check air filter: Inspect and replace a dirty air filter element.
• Inspect intake and exhaust: Ensure louvers, ducts, and exhaust piping are not blocked or collapsed.
• Turbocharger check: Listen for abnormal turbo noises and check for oil leaks. A failed turbo requires professional service.
• Re-test: After corrections, run under normal load and observe exhaust color and engine performance.