HomeCummins/OnanCummins/Onan E124V

Cummins/Onan E124V Generator Set

The Cummins/Onan E124V is a generator set.

2
Document types

How to read your Cummins/Onan serial & model number →

Service parts for the E124V

Grouped by system, with how many of each the parts manual calls for.

Oil system

1 required
965-0174BOil filtersee priceAmazon

Prices captured from merchant listings; some links are affiliate links. Confirm against your serial number before ordering.

Specifications

Ratings spec sheet not in our library yet — see the documents below.

Maintenance & consumables

ItemSpecCapacityPart #Interval
Air filterAir Cleaner Element Replacement: Remove the outer cover and wipe away loose dust and debris from the air cleaner assembly. Remove the inner air cleaner mounting nut and cover. Remove the air filter paper element and foam wrapper from the engine. Wipe off dust and debris from the air cleaner base. To keep anything from entering the carburetor and engine while the air cleaner element is off, place a piece of duct tape over the opening.100 hr
Fuel filter
Oil filterEngine Oil965-0174B Amazon eBay
Battery
Belt
Coolant
OilCheck the engine oil level with the oil dipstick (Figure 3). First park the equipment on a level surface, stop the engine and wait a minute or so to allow the oil to settle in the crankcase.25 hr
Spark plugSpark Arrestor Cleaning: Refer to Table 2 (Page 9) for scheduled spark arrestor cleaning. To clean the spark arrestor, remove the retaining screw and pull it from the muffler tail pipe. Use a wire brush or compressed air to clean the spark arrestor.100 hr

Service intervals

15
ItemActionHoursMonthsNotes
EngineInspect8 hrDaily or every 8 hours; check for oil, fuel and exhaust leaks, loose parts and unusual noises and vibrations
Oil LevelCheck8 hrKeep between Full and Add marks on dipstick.
Air Cleaner Foam WrapperClean50 hrPerform more often in dusty conditions.
Cylinder Cooling FinsClean50 hrPerform more often in dusty conditions.
Engine OilChange100 hrFirst service — Also after first 24 hours of operation as part of engine break-in; perform more often in dusty/hot conditions
Engine Oil and Oil FilterChange100 hrFirst service — Perform more often in hot or dusty conditions.
Spark PlugInspect100 hrInspect, clean and re-gap.
Air Cleaner ElementReplace200 hrPerform more often in dusty conditions.
Engine Oil FilterChange200 hrFirst service — Also after first 24 hours of operation as part of engine break-in; perform more often in dusty/hot conditions
Engine Valve ClearanceAdjust500 hrFirst service — Must be performed by a qualified mechanic.
Fuel FilterReplace200 hrIf so equipped.
Spark PlugReplace400 hr
Spark PlugsReplace500 hr
Cylinder Heads of DepositsClean1000 hrClean more often when using leaded fuel or running continuously under light load; Onan 4C cleaner recommended every 200 hours
Starting BatteryCheck1 moSee instructions for battery care provided by equipment or battery manufacturer

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

Service specifications

22
TypeItemValueUnitCondition
GapSpark Plug Gap0.025inches (0.64 mm)
GapSpark Plug Gap0.035inches
GapSpark Plug Gap0.89mm
OtherBore84.2mm
OtherCompression Ratio7.0 : 1
OtherCompression Ratio8.5:1
OtherDisplacement48inches3 (782 cc)
OtherIgnition Timing20° BTDCNon-adjustable electronic ignition
OtherIgnition Timing23° BTDCnon-adjustable, electronic magneto ignition
OtherStroke70.0mm
SpeedHigh Idle Speed3400RPMrecommended
SpeedLow Idle Speed1100RPMrecommended
SpeedLow Idle Speed1400RPMrecommended if no equipment spec
TorqueSpark Plug20lbs-ft
TorqueSpark Plug26N-m
TorqueSpark Plug Tightening Torque11lbs-ft (14 N-m)
Valve clearanceExhaust Valve Clearance0.006inchescold
Valve clearanceExhaust Valve Clearance0.013inches (0.33 mm)cold
Valve clearanceExhaust Valve Clearance0.15mmcold
Valve clearanceIntake Valve Clearance0.005inches (0.13 mm)cold
Valve clearanceIntake Valve Clearance0.006inchescold
Valve clearanceIntake Valve Clearance0.15mmcold

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 oil5W-30API Class SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)-28°C to 10°C1.9 l
Engine oil10W-30API SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)-18°C to 27°C1.6 l
Engine oil10W-30 or 10W-40API Class SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)-18°C to 27°C1.9 l
Engine oil10W-40API SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)-18°C to 27°C1.6 l
Engine oil15W-40API SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)-12°C to 38°C1.6 lOnaMax
Engine oil15W-40 (OnaMax)API Class SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)-12°C to 38°C1.9 l
Engine oilSAE 30API Class SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)above 0°C1.9 lSingle-grade SAE 30 oil is preferable when temperatures are consistently above freezing.
FuelUnleaded gasolineMinimum octane rating (Anti-Knock Index) of 87Do not use gasoline or additives containing methanol. Leaded gasoline may be used but increases maintenance.
Fuelunleaded gasolineminimum octane rating (Anti-Knock Index) of 87Do not use gasoline or gasoline additives containing methanol. Leaded gasoline may be used but will result in extra maintenance.

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
Choke Adjustment adjustment

Tools: 1/8 inch drill bit, wrench

  1. Shut off engine, remove air cleaner outer cover and filter element.
  2. Loosen choke rod swivel clamp screw.
  3. Lock throttle control lever with pin (1/8 inch drill bit) so pin acts as stop for choke lever.
  4. Push choke rod towards carburetor to fully open choke.
  5. Rotate choke lever towards carburetor until it bears against pin stop, tighten swivel clamp screw.
  6. Remove lock pin and check choke linkage operation. Replace damaged components.
  7. Reassemble air cleaner.
  8. Adjust throttle and choke control cables.
Control Cable Adjustments adjustment

Tools: 1/8 inch drill bit, wrench

  1. For single-cable: shut off engine, loosen throttle cable clamp.
  2. Lock throttle lever with pin (1/8 inch drill bit).
  3. Push speed control lever to high speed position.
  4. Hook cable wire into throttle lever, pull out slack, tighten clamp. Remove lock pin.
  5. For two-cable: repeat steps 1-3, then push choke knob to full-open.
  6. Hook choke cable wire into choke lever, push choke rod towards carburetor, pull out slack, tighten clamp.
Engine Speed Adjustment adjustment

⚠ Adjusting the engine speed to a value above that specified by the equipment manufacturer could cause the equipment to operate at speeds in violation of Federal and State Standards for Safety for the equipment.

⚠ Moving parts can cause severe personal injury or death. Take care when measuring engine speed with a tachometer and follow the meter instructions. You must be a qualified mechanic.

Tools: tachometer

  1. Normally no need to adjust engine speed. Instructions are for equipment manufacturer. Attempt only by qualified mechanic using accurate tachometer.
  2. Set low-idle and high-idle speeds to values specified in equipment Operator's Manual. If absent, adjust low-idle to 1,100 RPM and high-idle to 3,400 RPM.
  3. Start engine, observing all equipment manufacturer's instructions and precautions.
  4. If throttle cable already connected, loosen clamp at engine and back out low-idle speed stop screw so speed stop screw on carburetor touches its stop. Adjust engine speed to 1,000 RPM with carburetor
  5. Turn low-idle speed stop screw to obtain specified low-idle speed.
  6. Move engine throttle link up against its stop tang and hold it there while bending tang as necessary to obtain specified high-idle speed.
  7. Hook engine throttle link with throttle cable, pull slack out of throttle cable and tighten clamp. Check for full, smooth movement of engine throttle link between its two stop positions when equipment
Engine Speed Adjustments adjustment

⚠ Adjusting engine speed above equipment manufacturer spec could cause violation of safety standards.

⚠ Moving parts can cause severe personal injury or death.

Tools: tachometer, 1/8 inch drill bit, wrench

  1. Remove outer cover of air cleaner and set up tachometer.
  2. Start engine.
  3. Lock throttle control lever with pin (1/8 inch drill bit) in control plate.
  4. Loosen choke rod swivel clamp screw and push choke rod towards carburetor to fully open choke.
  5. Adjust high-idle speed by rotating engine control plate. Loosen pivot bolt 1/8 turn and set bolt 1/4 turn. Retighten.
  6. Adjust low-idle speed by turning idle speed screw. Remove lock pin and move throttle to lowest position.
  7. Shut off engine and readjust choke.
Air Cleaner Maintenance maintenance
  1. Refer to Table 2 for scheduled foam wrapper maintenance and air cleaner element replacement. See Figure 4.
  2. For foam wrapper only: do not remove inner air cleaner cover. Remove and wash foam wrapper in water and detergent.
  3. Squeeze foam wrapper dry like a sponge. Rinse with clean water and allow to dry.
  4. Coat wrapper evenly with one tablespoon (14 grams) of SAE 30 engine oil. Knead oil into wrapper and wring out excess oil.
  5. Install foam wrapper over paper air cleaner element by stretching it over inner cover. Completely cover all exposed paper pleats.
  6. Replace foam wrapper when it becomes torn or stretched.
  7. For element replacement: pull choke knob to full-choke position to close choke plate. Remove outer cover and wipe away loose dust and debris.
  8. Remove inner air cleaner mounting nut and cover.
  9. Remove air filter paper element and foam wrapper from engine. Wipe off dust and debris from air cleaner base.
  10. Install new paper element and secure with inner cover and mounting nut. Reinstall foam wrapper and outer cover. Reconnect crankcase breather tube.
Daily (8 Hour) Maintenance maintenance

⚠ Hot exhaust parts can cause severe burns. Allow the engine time to cool before servicing the exhaust system.

⚠ A clogged flywheel air inlet screen or dirty cooling fins can cause overheating and engine damage. Keep cooling fins and air inlet screen clean.

⚠ Crankcase pressure can blow hot engine oil out the fill tube causing severe burns. Always stop the engine before removing the oil fill cap.

  1. Inspect fuel lines and fittings for leaks. Repair leaks immediately.
  2. Look and listen for exhaust system leaks while engine is running. Look for cracks and severe rusting in muffler and tailpipe. Have all leaks repaired before continuing operation.
  3. Check engine for dirt and debris and clean flywheel air inlet screen and cylinder cooling fins as necessary.
  4. Check engine oil level. Equipment must be parked on level surface and engine stopped. Wait a minute for oil to settle. Turn oil fill cap counterclockwise and lift from fill tube. Wipe dipstick clean a
  5. If oil level is low, add API Class SG or SH oil having SAE viscosity grade appropriate for expected temperatures, as indicated by Table 1. Do not fill above Full mark.
  6. Reinstall dipstick and cap after checking or adding oil, turning clockwise until secure.
Engine Break-in maintenance
  1. Operate equipment at about half power for first 1-1/2 hours, occasionally full power briefly. Avoid prolonged low-speed, low-power operation.
  2. Use proper engine oil for ambient temperatures.
  3. Check oil level twice a day or after every 4 hours during first 24 hours.
  4. Change oil and oil filter after first 24 hours and have valves readjusted by qualified mechanic.
Engine Oil and Filter Change maintenance

⚠ State and federal agencies have determined that contact with used engine oil can cause cancer or reproductive toxicity. Take care to limit skin contact and breathing of vapors. Use rubber gloves and wash exposed skin.

⚠ Accidental starting of the engine can result in severe personal injury or death. Always disconnect the spark plug and the battery (negative [–] cable) before changing oil.

⚠ Crankcase pressure can blow hot engine oil out the fill opening causing severe burns. Always stop the genset before removing the oil fill cap.

Tools: pan, rubber gloves

  1. Run engine until warm, stop engine, disconnect spark plug and battery (negative cable first).
  2. Remove oil fill cap.
  3. Place a pan under oil drain opening and remove oil drain plug; reinstall plug securely after oil has drained completely.
  4. Spin off oil filter canister, drain oil, and discard filter according to local regulations.
  5. Thoroughly wipe off filter mounting surface.
  6. Make sure gasket is in place on filter canister and apply a thin film of oil to gasket.
  7. Spin on new filter canister by hand until gasket just touches mounting pad, then turn an additional 1/2 to 3/4 turn. Do not overtighten.
  8. Refill with API Class SG or SH oil having SAE viscosity grade appropriate for expected temperatures. See Specifications for oil capacity.
  9. Reconnect spark plug and battery.
  10. Start engine and run for a short time while checking for oil leaks around drain plug and oil filter. Do not overtighten.
  11. Pour used oil into sealed container and deliver to nearest recycling center.
Fuel Filter Replacement maintenance

⚠ Gasoline is highly flammable and can cause severe personal injury or death.

  1. Let engine cool, close fuel shutoff valve.
  2. Disconnect fuel line from filter, taking care not to spill fuel.
  3. Remove old filter (in-line type: loosen hose clamps).
  4. Install new filter, secure connections.
  5. Open fuel valve, check for leaks.
Out-of-Service Protection maintenance

⚠ Gasoline preservatives are toxic.

  1. Run engine to normal temperature, shut off fuel, let engine stop. Add fuel preservative if storing >120 days.
  2. Drain oil while warm, refill with fresh oil, tag with viscosity.
  3. Remove spark plug, squirt 1 ounce (2 tablespoons or 28 grams) rust inhibitor or SAE 30 oil into cylinder. Crank a few times, reinstall spark plug.
  4. Perform air cleaner maintenance.
  5. Clean governor linkage and wrap with cloth.
  6. Plug exhaust outlet.
  7. Provide cover for unit.
  8. Disconnect battery (negative first) and follow storage instructions.
Returning the Engine to Service maintenance
  1. Remove cover, protective wrapping, and exhaust plug.
  2. Check oil tag; change oil if viscosity not appropriate.
  3. Check fuel filter and fuel lines for security and leaks.
  4. Check choke, throttle, governor linkages move freely.
  5. Clean and check battery, connect cables (positive first).
  6. Start engine. Initial startup may be slow, smoke, rough operation until oil burns off. If no start, clean or replace spark plug.
Spark Plug Maintenance and Replacement maintenance

Tools: wrench, torque wrench

  1. Thread spark plug in by hand until it seats to prevent crossthreading.
  2. If reusing, turn with wrench additional 1/4 turn. If new, additional 3/8 to 1/2 turn.
  3. If using torque wrench, tighten to 20 lbs-ft (26 N-m).

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 oil filter fits the Cummins/Onan E124V?

The Cummins/Onan E124V uses oil filter part number 965-0174B.

Troubleshooting

3

Symptoms & remedies

SymptomRemedy
The diagnostics light on the electronic control unit should go off in about 30 seconds after the engine starts.Check the vacuum hose if the light blinks during the first 30 seconds and reattach it if loose. Have the engine serviced if that does not help.
The engine will shut down in a few minutes if the diagnostics light comes on and stays on.Have the engine serviced if it shuts down with the light on. Service will also be required if the light blinks or comes on intermittently while the engine is running.
The diagnostics light blinks or comes on intermittently while the engine is running.Have the engine serviced if it shuts down with the light on. Service will also be required if the light blinks or comes on intermittently while the engine is running.

Fault codes and symptom→remedy steps extracted from this model’s service/owner documentation; verify against the official manual before servicing.

Parts

45
Part #DescriptionQtySystem
146-0484Gasket1Gasket Amazon eBay
148-1076Sensor, Oxygen1Sensor Amazon eBay
155-2378Gasket1Gasket Amazon eBay
509-01420-Ring1Seal Amazon eBay
509-0269Seal, Oil Fill Tube1Seal Amazon eBay
509-0304Gasket, Spacer-Air Cleaner (0.625")1Gasket spacer air cleaner Amazon eBay
965-0174BEngine OilOil filter Amazon eBay
EB776Governor Lever1Governor lever Amazon eBay
123-1873-02Tube, Oil Fill1Service part / kit Amazon eBay
123-1874Filter, Breather Tube1Service part / kit Amazon eBay
123-1874-01Indicator, Oil Level (Includes O’Ring) Code 17DP (Notched Cap)1Service part / kit Amazon eBay
123-1876Bracket, Support1Service part / kit Amazon eBay
123-2105Adapter Assy (Includes O’Rings (Code 17DP))1Service part / kit Amazon eBay
134-4738Guard, Stationary1Service part / kit Amazon eBay
134-4739-50Housing, Blower1Service part / kit Amazon eBay
134-4743-50Deflector, Air1Service part / kit Amazon eBay
134-4978-02Deflector, Air (Spec 11531)1Service part / kit Amazon eBay
140-2810Tube, Air Inlet1Service part / kit Amazon eBay
140-2824-02Support, Precleaner1Service part / kit Amazon eBay
140-2825-01Filter, Precleaner1Service part / kit Amazon eBay
140-2853-02Cover, Precleaner1Service part / kit Amazon eBay
148-1003-03Bracket, Carburetor Guard1Service part / kit Amazon eBay
154-2792Elbow, Intake1Service part / kit Amazon eBay
191-2207Regulator, Voltage1Service part / kit Amazon eBay
526-0115Washer (5/16 “)2Service part / kit Amazon eBay
718-10176 M6 X 10 MM3Service part / kit Amazon eBay
718-10328 M8 X 10 MM1Service part / kit Amazon eBay
718-1041Screw, Hex Head Cap (M8 x 1.25 x 45mm)2Service part / kit Amazon eBay
725-1051Screw, Socket Head Cap2Service part / kit Amazon eBay
740-10048 ] - Phase4Service part / kit Amazon eBay
740-1006Part 740-10061Service part / kit Amazon eBay
750-1006Nut, Hex (M8)1Service part / kit Amazon eBay
800-2063Screw, Hex Head Cap (M8 x 1.25 x 50mm)2Service part / kit Amazon eBay
815-0340Screw, Hex Washer Head (#10–32 x 3/8’’)12Service part / kit Amazon eBay
815-0474Screw, Hex Washer Head (Sheet Metal (1/4–14 x 1/2’'))1Service part / kit Amazon eBay
815-0576Screw, Cross Recessed Self-Tapping Pan Head (#10 x 1-1/4’’)1Service part / kit Amazon eBay
815-0659Screw, Torx Drive4Service part / kit Amazon eBay
815-0709-01Screw, Hex Head Thread Form1Service part / kit Amazon eBay
815-0753Screw, Self Tapping (M6 x 14mm)1Service part / kit Amazon eBay
815-0756Bolt, Flange Hex Head (M6 x 1 x 14mm)4Service part / kit Amazon eBay
821-2033Screw, Lock Flange (M6 x 1 x 16mm)3Service part / kit Amazon eBay
823-1003Screw, Button (M6 x 1 x 20mm)4Service part / kit Amazon eBay
870-0131Nut. Hex - with ET (#10-32)2Service part / kit Amazon eBay
870-0410Nut, Speed - Begin Spec C1Service part / kit Amazon eBay
870-2055Nut, Lock Flange (M8 x2Service part / kit Amazon eBay

Service, wear & replacement parts referenced for this model and its engine — confirm the exact part for your serial number. See the full parts catalog to search and cross-reference.

Available documents

Operator's manual — 965-0178 Onan E125V E140V Elite series Operator's manual (07-1997) (Cummins/Onan)Operator's manual — 965-0180 Onan P218V P220V Performer series Engine Operator's manual (07-1997) (Cummins/Onan)Parts manual — 965-0200 Onan E124V E125V E140V LP Parts Manual (12-1998) (Cummins/Onan)Service manual — 965-0174B Onan E124V Floor Care Operators Manual (12-2000) (Cummins/Onan)Service manual — 965-0764 Onan E124V E125V E140V Elite series Engine Service manual 11-1997 (archive.org)