Yanmar LW SERIES Engine Engine

• Engine will not start; or starts and runs rough.
  Cause: 1. Incorrect start sequence. 2. Fuel valve is OFF. 3. Dirty air filter. 4. Out of fuel. 5. Stale or contaminated fuel. 6. Low oil level. 7. Excessive rich fuel mixture. 8. Dirty fuel filter. 9. Air in fuel system. 10. Engine is under electrical load. 11. Battery not installed. 12. Battery weak or dead.
  Fix: 1. Review & follow starting procedure. 2. Turn fuel valve ON. 3. Clean or replace air filter. 4. Fill fuel tank. 5. Drain fuel tank and fill with fresh fuel. 6. Fill crankcase to correct level. 7. Contact Authorized Service Dealer. 8. Replace fuel filter. 9. Repeat priming procedure. If no start condition persists Contact Authorized Service Dealer. 10. Remove all equipment from receptacles. Make sure the main breaker switch is OFF. 11. Install battery. 12. Charge or replace battery.
• Engine surges or stumbles.
  Cause: 1. Governor/throttle assembly is not adjusted properly. 2. Air
• Engine shuts down during operation.
  Cause: 1. Out of fuel. 2. Low oil level. 3. Fault in engine. 4. Ambient temp too high. 5. Battery weak or dead.
  Fix: 1. Fill fuel tank. Prime fuel system. See Starting Pull Start Engines or Starting Electric Start Engines 2. Fill crankcase to correct level. 3. Contact Authorized Service Dealer. 4. Move unit to cooler location and allow engine to cool before running again. 5. Charge or replace battery.
• Engine runs well at no-load, but bogs when load is applied.
  Cause: 1. Short circuit in a connected load. 2. Generator is overloaded. 3. Engine speed is too slow. 4. Shorted generator circuit.
  Fix: 1. Disconnect shorted electrical load. 2. See Know Generator Limits 3. Contact Authorized Service Dealer. 4. Contact Authorized Service Dealer.
• Engine lacks power.
  Cause: 1. Load is too high. 2. Dirty air filter. 3. Engine needs to be serviced. 4. Excessive valve lash. 5. Dirty fuel filter. 6. Fuel injector clogged.
  Fix: 1. Reduce load. See Know Generator Limits 2. Clean or replace air filter. 3. Contact Authorized Service Dealer. 4. Contact Authorized Service Dealer. 5. Replace fuel filter. 6. Contact Authorized Service Dealer.
• Engine is running, but AC output is not available.
  Cause: 1. Circuit breaker OPEN. 2. Poor connection or defective cord set. 3. Connected device is bad. 4. Fault in generator. 5. Main breaker switch is OFF. 6. Voltage selector switch is OFF. 7. Generator is overloaded. 8. GFCI outlet has tripped.
  Fix: 1. Reset circuit breaker. 2. Check and repair. 3. Connect another device that is in good condition. 4. Contact Authorized Service Dealer. 5. Switch main breaker ON. 6. Switch voltage selector switch to desired voltage output. 7. See Know Generator Limits 8. Correct ground fault in circuit and reset GFCI.

Compiled from service & troubleshooting documentation across every generator set that uses the Yanmar LW SERIES.