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Yanmar LW Series Engine

The Yanmar LW Series is a 0.43 L engine rated at 3600 rpm. It powers generator sets from Generac, including the XD5000E. It holds 1.6 L (0.4 gal) of oil.

Also known as: Yanmar LW Series

0.435 L
Displacement
3600 rpm
Rated speed
1.6 L
Oil capacity
On this pageSpecsGenerator setsMaintenanceFAQService intervalsFluidsProceduresWiring

Engine specifications

Oil capacity1.6 L
Displacement0.435 L
Rated speed3600 rpm

Common problems

6
  • Engine surges or stumbles.
    Cause: 1. Governor/throttle assembly is not adjusted properly. 2. Air in fuel system.
    Fix: 1. Contact Authorized Service Facility. 2. Contact Authorized Service Facility.
  • Engine shuts down during operation.
    Cause: 1. Out of fuel. 2. Low oil level. 3. Fault in engine. 4. Ambient temp too high.
    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 Facility. 4. Move unit to cooler location and allow engine to cool before running again.
  • 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.
    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 Facility. 8. Replace fuel filter. 9. Contact Authorized Service Facility. 10. Remove all equipment from receptacles. Make sure the main breaker switch is OFF.
  • 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 Facility. 4. Contact Authorized Service Facility.
  • 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 Facility. 4. Contact Authorized Service Facility. 5. Replace fuel filter. 6. Contact Authorized Service Facility.
  • 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 Facility. 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.

Maintenance schedule

ItemSpecCapacityPart #Interval
OilSAE 10W-301.6 L—50 hr

Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.

Service intervals

18
ItemActionHoursMonthsNotes
Engine oil levelCheck8 hrat each use / every 8 hours of operation
Hour meter oil change alertOther100 hrCHG OIL display illuminates every 100 hours (hour meter alert)
Air cleaner filterClean200 hrEvery 200 hours or every season; more often under dirty/dusty conditions
Air cleaner filterInspect200 hrevery 200 hours or every season; clean more often in dirty/dusty conditions
Engine oil and oil filterChange200 hrFirst service — change after first 50 hours, then every season; every month under heavy load or high temperature
Engine speed controlCheck200 hrevery 200 hours or every season
Fuel tank / outlet fuel filterDrain200 hrdrain fuel tank and replace outlet fuel filter every 200 hours or every season
Fuel tank and outlet fuel filterDrain200 hrEvery 200 hours or every season; drain fuel tank & replace outlet fuel filter
Hour meter service alertOther200 hrSVC display illuminates every 200 hours (hour meter alert - service air filter)
Oil and oil filterChange200 hrEvery 200 hours or every season; change after first 50 hours then every season; more often under heavy load/high temp
Valve clearanceAdjust400 hrFirst service — check and adjust if necessary after first 50 hours, then every 400 hours thereafter
Valve clearanceCheck400 hrFirst service — Every 400 hours thereafter (also check every season)
CompressionCheck1000 hr
Engine compressionCheck1000 hr
Fuel injection nozzleInspect1500 hrinspect, clean and test
Fuel hosesCheck2000 hrcheck and replace
Generator start/run during storageTest1 moStart and run the generator for 30 minutes every 30 days during storage
Stored fuel treatment testTest3 moTest stored fuel every 90 days and provide additional treatment if required

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Recommended fluids

FluidGradeStandardAmbientCapacityNotes
Engine oilSAE 20W-40CI-4 or CJ-41.6 L (1.7 qt)Recommended for general, all-temperature use; viscosity chart also lists SAE 15W-40, 20W, 30, 40, 10W-30, 10W by ambient temperature from -20°C to 40°C
Engine oilSAE 10W-20°C to 0°C1.6 L (1.7 qt)see viscosity chart
Engine oilSAE 10W-30-20°C to 20°C1.6 L (1.7 qt)see viscosity chart
Engine oilSAE 15W-40-10°C to 40°C1.6 L (1.7 qt)see viscosity chart
Engine oilSAE 20W-10°C to 30°C1.6 L (1.7 qt)see viscosity chart (appears twice on chart for different temperature bands)
Engine oilSAE 300°C to 40°C1.6 L (1.7 qt)see viscosity chart
Engine oilSAE 4010°C to 40°C1.6 L (1.7 qt)see viscosity chart
Engine oilSAE 20W-40 (general, all-temperature); chart also lists SAE 15W-40, 20W, 30, 40 (mineral) and SAE 10W-30, 20W, 10W (synthetic) by ambient temperatureAPI service class CI-4 or CJ-420°C to 40°C1.6 L (1.7 qt)Temperature scale on chart: -20°C/-4°F to 40°C/104°F
FuelDiesel45.4 L (12 U.S. gallons)always treat diesel fuel for long-term storage with approved fuel additive and water abatement material; test stored fuel every 90 days
FuelNo. 2D diesel (above freezing); blend of No.1D and No.2D below freezingSulfur content max 15 ppm; minimum Cetane index of 4045.4 L (12 U.S. gallons)Do not use home heating oil or bio-diesel
FuelNo. 2D diesel above freezing; blend of No. 1D and No. 2D diesel below freezingSulfur content 15 ppm maximum; minimum Cetane index of 4045.4 L (12 U.S. gallons)Do NOT use Home Heating Oil or Bio-Diesel Fuel

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Procedures

12
Change Engine Oil maintenance

⚠ Allow engine to cool before draining oil; failure to do so could result in death or serious injury (risk of burns).

  1. Place generator on a level surface.
  2. Clean area around oil fill and oil drain plug.
  3. Remove oil fill cap.
  4. Remove oil drain plug and drain oil completely into a suitable container.
  5. Install oil drain plug and tighten securely.
  6. Slowly pour oil into the oil fill opening until level is between the crosshatch marks on the dipstick; do not overfill.
  7. Install oil fill cap and finger tighten.
  8. Wipe up any spilled oil.
  9. Properly dispose of oil in accordance with all applicable regulations.
Inspect Engine Oil Level maintenance

⚠ Verify proper type and quantity of engine oil prior to starting to avoid engine damage

  1. Place generator on a level surface.
  2. Clean area around oil fill.
  3. Remove oil fill cap and wipe dipstick clean.
  4. Screw dipstick into filler neck; verify oil level is within safe operating range.
  5. Add recommended engine oil as necessary.
  6. Replace oil fill cap and hand-tighten.
Prepare Fuel System for Storage maintenance

⚠ Eye protection required to avoid spray from spark plug hole when cranking engine

⚠ Explosion and fire risk: store fuel in well-ventilated area away from ignition sources

  1. Push and hold decompression lever down; pull recoil starter/crank engine 2-3 seconds without starting.
  2. Pull decompression lever up; pull recoil slowly until resistance is felt, then gently release.
  3. Completely drain fuel tank or completely fill fuel tank to proper level.
  4. Treat diesel fuel with approved fuel additive and water abatement material for long-term storage.
  5. Change engine oil before storage.
Prepare Fuel System for Storage (Recoil Start) maintenance

⚠ Treat diesel fuel for long-term storage; test stored fuel every 90 days

  1. Push and hold decompression down, slowly pull recoil starter 2-3 times (do not start)
  2. Pull decompression lever up, pull recoil slowly until resistance felt to close valves
  3. Completely drain fuel tank or completely fill to proper level
Prepare Fuel System for Storage - Electric Start maintenance

⚠ Eye protection is required to avoid spray from spark plug hole when cranking engine.

  1. Push and hold decompression lever down.
  2. Push Start/Run/Stop switch to turn the engine for 2 to 3 seconds; do not start engine.
  3. Pull decompression lever up; pull recoil slowly until resistance is felt (closes valves so moisture cannot enter engine cylinder); gently release recoil.
  4. Completely drain fuel tank or completely fill fuel tank to proper level.
Prepare Fuel System for Storage - Recoil Start maintenance

⚠ Eye protection is required to avoid spray from spark plug hole when cranking engine.

  1. Push and hold decompression down and slowly pull recoil starter 2 to 3 times; do not start engine.
  2. Pull decompression lever up; pull recoil slowly until resistance is felt (closes valves so moisture cannot enter engine cylinder); gently release recoil.
Service Air Filter maintenance
  1. Turn knob and remove air filter cover.
  2. Wash in soapy water; squeeze filter dry in a clean cloth (do not twist).
  3. Clean air filter cover before re-installing it.
Emergency Shutdown Procedure operation
  1. Press down on the small red lever on the lower engine controls (near recoil handle and dipstick) to the Stop position.
  2. Turn main breaker switch Off.
  3. Switch engine start switch to Off.
  4. Turn fuel valve Off.
Generator Shut Down operation
  1. Turn main breaker switch Off.
  2. Switch engine start switch to Off.
  3. Turn fuel valve Off.
Return Engine to Service operation

⚠ Avoid prolonged operation at minimum or maximum engine speeds and loads for the first hour of operation

  1. Refer to the Before Starting Engine section.
  2. Start engine and run at no load for 5 to 10 minutes.
  3. Check oil pressure.
  4. Check for fuel, engine oil, or coolant leaks.
  5. Check proper operation of indicators/gauges.
Starting Electric Start Engines operation

⚠ Disconnect electrical loads prior to starting or stopping unit.

  1. Turn main breaker switch to Off.
  2. Unplug all electrical loads from the unit's receptacles before starting engine.
  3. Place generator on a level surface.
  4. Turn fuel valve On.
  5. Switch engine control lever to Run.
  6. Squeeze primer bulb 5-10 times until firm; fuel filter should show fuel level at least half full.
  7. Press and hold the Engine Start switch until engine starts; release if it does not start within 5 seconds.
  8. Turn Main Breaker to On.
  9. Select voltage rating with the Voltage Selector.
Starting Pull Start Engines operation

⚠ Recoil Hazard: recoil could retract unexpectedly, causing death or serious injury.

⚠ Disconnect electrical loads prior to starting or stopping unit.

  1. Unplug all electrical loads from the unit's receptacles before starting engine.
  2. Place generator on a level surface.
  3. Turn main breaker switch Off.
  4. Turn fuel valve On.
  5. Switch engine control lever to Run.
  6. Press control panel engine Run/Stop switch to Run.
  7. Squeeze primer bulb 5-10 times until firm; fuel filter should show fuel level at least half full.
  8. Firmly grasp recoil handle, pull slowly until resistance is felt, flip red decompression lever, then pull rapidly up and away.
  9. Repeat until engine starts; if it does not start within 5 pulls, confirm steps 1-6 and repeat the primer step.
  10. Allow engine to run at least 10 seconds, then turn main breaker On.
  11. Select voltage rating with the voltage selector.

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Voltage reconnection

VoltagePhaseConnectionLeadsNotes
120/240SingleL14-30 (models 6852-6854)30 Amp inlet for 6852-6854; CS6377 inlet for 9854-9855 (50 Amp)

Extracted from the manufacturer documentation linked to this model. Values are copied as printed; confirm against your unit's manual and serial number.

Common questions

What is the oil capacity of the Yanmar LW Series?

The Yanmar LW Series engine has an oil capacity of 1.6 liters.

What is the displacement of the Yanmar LW Series?

The Yanmar LW Series has a displacement of 0.435 liters.

Which generators use the Yanmar LW Series engine?

The Yanmar LW Series powers 1 generator set(s), including Generac XD5000E.

How often should you change the oil in the Yanmar LW Series?

The Yanmar LW Series oil change interval is every 50 hours.

What is a common problem with the Yanmar LW Series engine?

A commonly reported issue on generators using the Yanmar LW Series is: Engine surges or stumbles.. Cause: 1. Governor/throttle assembly is not adjusted properly. 2. Air in fuel system.. Fix: 1. Contact Authorized Service Facility. 2. Contact Authorized Service Facility..