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Cummins/Onan E140H Engine

Name: Cummins/Onan E140H Engine
Brand: Cummins/Onan

The Cummins/Onan E140H is a 390 L pressure lubrication engine rated at 3600 rpm, producing up to 10.4 kW. It powers generator sets from Cummins/Onan, including the E140. It holds 0.9 L (0.2 gal) of oil.

Also known as: Onan E140H

390.0 L

Displacement

3600 rpm

Rated speed

10 kW

Gross power

0.9 L

Oil capacity

On this pageSpecs Generator sets Maintenance FAQ Service intervals Torque & specs Fluids Procedures

Engine specifications

Oil capacity	0.9 L
Displacement	390.0 L
Aspiration	pressure lubrication
Rated speed	3600 rpm
Gross power	10 kW

Generator sets powered by this engine

Cummins/Onan E140

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

Common problems

Weakness and Sleepiness
Fix: Get out into fresh air immediately, shut down the unit and do not use it until it has been inspected.
Vomiting
Fix: Get out into fresh air immediately, shut down the unit and do not use it until it has been inspected.
The engine runs and then stops.
Fix: A. Check the fuel tank and fill if necessary. b. Check the engine oil level and add oil as necessary. Drain excess oil if the level is above the dipstick Full mark. c. Reconnect and reclamp the choke and throttle cables, if necessary. See Adjustments.
The engine fails to crank (electric start engines).
Fix: A. Release the clutch (if so equipped). b. Clean and tighten the positive (+) and negative (–) battery cable connections at the battery and the engine. c. Recharge the battery. Refer to the equipment or battery manufacturer’s recommendations.
The engine exhausts black smoke.
Fix: A. Service the air cleaner. b. Reconnect and reclamp the choke and throttle cables, if necessary. See Adjustments.
The engine cranks slowly (electric start), or the recoil starter is hard to pull.
Fix: A. Release the clutch (if so equipped). b. If electric start, clean and tighten the positive (+) and negative (–) battery cable connections at the battery and the engine. c. If electric start, recharge the battery. Refer to the equipment or battery manufacturer’s recommendations. d. Change engine oil to oil having the proper viscosity for the ambient temperature. See Table 1.
The engine cranks but fails to start.
Fix: A. Check the fuel tank and fill if necessary. b. Open any closed fuel shut off valve. c. Check engine oil level and add oil as necessary. d. Reconnect and reclamp the choke and throttle cables, if necessary. See Adjustments. e. Service the air cleaner. f. Replace the fuel filter(if provided). g. Inspect and clean or replace the spark plug and re-gap it.
Muscular Twitching
Fix: Get out into fresh air immediately, shut down the unit and do not use it until it has been inspected.
Inability to Think Coherently
Fix: IF YOU OR ANYONE ELSE EXPERIENCE ANY OF THESE SYMPTOMS, GET OUT INTO THE FRESH AIR IMMEDIATELY. If symptoms persist, seek medical attention. Shut down the engine and do not operate it until it has been inspected and repaired.
Dizziness
Fix: Get out into fresh air immediately, shut down the unit and do not use it until it has been inspected.

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan E140H.

Maintenance schedule

Item	Spec	Capacity	Part #	Interval
Air filter	High capacity air cleaner		—	200 hr
Fuel filter	Genuine Onan Maintenance Parts and Products		—	400 hr
Oil filter	Genuine Onan Maintenance Parts and Products		—	200 hr
Oil	Genuine Onan Maintenance Parts and Products	1.0 qt	—	24 hr
Spark plug			—	24 hr

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

Repair guides

Governor/Throttle Adjustments

Step-by-step procedures compiled from the Cummins/Onan service manual for this engine.

Service intervals

Item	Action	Hours	Months	Notes
Engine	Inspect	8 hr		Daily or every 8 hours; check for oil, fuel and exhaust leaks, loose parts and unusual noises and vibrations
Exhaust System	Inspect	8 hr		Daily or every 8 hours
Fuel Lines	Inspect	8 hr		Daily or every 8 hours
Oil Level	Check	8 hr		Keep between Full and Add marks on dipstick.
Air Cleaner Foam Wrapper	Clean	50 hr		Perform more often in dusty conditions.
Cylinder Cooling Fins	Clean	50 hr		Perform more often in dusty conditions.
Engine Oil	Change	100 hr		First 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 Filter	Change	100 hr		First service — Perform more often in hot or dusty conditions.
Spark Plug	Inspect	100 hr		Inspect, clean and re-gap.
Air Cleaner Element	Replace	200 hr		Perform more often in dusty conditions.
Engine Oil Filter	Change	200 hr		First service — Also after first 24 hours of operation as part of engine break-in; perform more often in dusty/hot conditions
Engine Valve Clearance	Adjust	500 hr		First service — Must be performed by a qualified mechanic.
Fuel Filter	Replace	200 hr		If so equipped.
Spark Plug	Replace	400 hr
Spark Plugs	Replace	500 hr
Cylinder Heads of Deposits	Clean	1000 hr		Clean more often when using leaded fuel or running continuously under light load; Onan 4C cleaner recommended every 200 hours
Starting Battery	Check		1 mo	See 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

Type	Item	Value	Unit	Condition
Clearance	Connecting rod large bore clearance	0.015-0.050	mm	allowable limit 0.100
Clearance	Connecting rod side clearance on crankshaft	0.40-1.10	mm	allowable limit 1.50
Clearance	Cylinder bore I.D. standard	84.200-84.225	mm	factory specification; allowable limit 84.325
Clearance	Cylinder bore out-of-round allowable limit	0.05	mm	0.002 in
Clearance	Cylinder bore taper allowable limit	0.10	mm	0.004 in
Clearance	Valve stem to valve guide clearance (exhaust)	0.04-0.08	mm	allowable limit 0.10
Clearance	Valve stem to valve guide clearance (intake)	0.03-0.06	mm	allowable limit 0.10
Gap	Magneto coil to rotor magnet clearance (air gap)	0.25-0.40	mm	0.010-0.016 in
Gap	Spark Plug Gap	0.025	inches (0.64 mm)
Gap	Spark Plug Gap	0.035	inches
Gap	Spark Plug Gap	0.035 inches (0.89 mm)	inches (mm)
Gap	Spark Plug Gap	0.89	mm
Gap	Spark plug gap	0.89-1.02	mm	0.035-0.040 in
Other	Bore	84.2	mm
Other	Carburetor CO adjustment	5% to 6% CO at 3300 rpm	CO	no load; without meter set idle mixture screw 2 turns out
Other	Compression Ratio	7.0 : 1
Other	Compression Ratio	8.5	:1
Other	Displacement	48	inches3 (782 cc)
Other	Ignition Timing	20° BTDC		Non-adjustable electronic ignition
Other	Ignition Timing	23	° BTDC	non-adjustable, electronic magneto ignition
Other	Ignition Timing	23° BTDC	degrees BTDC	Non-adjustable, electronic, magneto ignition
Other	Ignition timing (not adjustable)	23	degrees BTDC	fixed by flywheel magnet to shaft keyway relationship
Other	Stroke	70.0	mm
Pressure	12 VDC system voltage regulator output	13.6-14.7	VDC	@ any speed within operating range
Pressure	Minimum cylinder compression test pressure	483	kPa	warm engine at cranking speed (about 300 rpm); 70 psi
Resistance	Alternator stator resistance	5 amp system: 0.54 to 0.66; 20 amp system: 0.27 to 0.33	Ohms
Speed	High Idle Speed	3400	RPM	recommended
Speed	High-Idle Speed	3400	RPM	recommended in absence of equipment specifications
Speed	Low Idle Speed	1100	RPM	recommended
Speed	Low Idle Speed	1400	RPM	recommended if no equipment spec
Speed	Low-Idle Speed	1400	RPM	recommended in absence of equipment specifications
Speed	Recommended high-idle engine speed	3400	RPM	when equipment manufacturer spec not available
Speed	Recommended low-idle engine speed	1400	RPM	when equipment manufacturer spec not available
Torque	Adapter Filter Head	47-54	N-m	3/4"-16 (35-40 lb-ft)
Torque	Air Cleaner Pan to Cylinder Block	11-16	N-m	M8 x 16 (8-12 lb-ft); tighten twice (1-2-1)
Torque	Alternator Stator Screws	10-15	N-m	M6 x 25 (7-11 lb-ft)
Torque	Blower Housing Bolts	7-11	N-m	M6 x 20 (5-8 lb-ft)
Torque	Blower Housing to Manifold Bolt	10-15	N-m	M6 x 14 (7-11 lb-ft)
Torque	Carburetor to Intake Elbow	10-15	N-m	M6 x 85 (7-11 lb-ft); tighten twice (1-2-1)
Torque	Chaff Screen Bolts	7-11	N-m	M6 x 10 (5-8 lb-ft)
Torque	Connecting Rod Bolts	24-27	N-m	bolt M8 x 44 (18-20 lb-ft)
Torque	Connector-Wire Harness to Blower Housing	1.4-2	N-m	M4 x 12 (12-18 lb-in)
Torque	Control Plate Screws	7-9.5	N-m	M5 x 16, 30 (5-7 lb-ft)
Torque	Cylinder Air Housing	7-11	N-m	M6 x 10 (5-8 lb-ft)
Torque	Cylinder Air Housing Bolt	11-16	N-m	M8 x 16 (8-12 lb-ft)
Torque	Cylinder Head Bolts No. 1-5	42-50	N-m	M10 x 66, 86, 125 (31-37 lb-ft); torque in sequence, retorque bolts 2 & 4 last
Torque	Cylinder Head No. 6 Flange Bolt	16-22	N-m	M8 x 50 (12-16 lb-ft)
Torque	Flywheel Nut	122-138	N-m	M18 (90-102 lb-ft)
Torque	Fuel Line Hold Down Screw	1.4-2	N-m	#10-16 (12-18 lb-in)
Torque	Fuel Pump Pulse Line Elbow	7-9.5	N-m	1/8" NPT (5-7 lb-ft)
Torque	Gearcase Bolts	16-22	N-m	M8 x 35, 50, 75 (12-16 lb-ft); clockwise from bolt A, torque A twice
Torque	Governor Arm Nut	8.1-10.9	N-m	M6 (6-8 lb-ft)
Torque	Ignition Coil Bolt	10-15	N-m	M6 x 30 (7-11 lb-ft)
Torque	Intake Elbow to Cylinder Head	11-16	N-m	M8 x 50 (8-12 lb-ft)
Torque	LOPCO or Pipe Plug	7-9.5	N-m	1/8" NPT (5-7 lb-ft)
Torque	Oil Drain Plugs	7-11	N-m	1/4" NPT (5-8 lb-ft)
Torque	Oil Fill Tube	11-16	N-m	M8 x 20 (8-12 lb-ft)
Torque	Oil Pickup Tube	7-11	N-m	M6 x 14 (5-8 lb-ft)
Torque	Oil Pump Cover Screws	7-11	N-m	M6 x 14 (5-8 lb-ft)
Torque	Pulse Pump to Air Cleaner Pan	2.3-2.8	N-m	#10 (20-25 lb-in)

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

Fluid	Grade	Standard	Ambient	Capacity	Notes
Engine oil	5W-30	API Class SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)	-28°C to 10°C	1.9 l
Engine oil	10W-30	API SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)	-18°C to 27°C	1.6 l
Engine oil	10W-30 or 10W-40	API Class SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)	-18°C to 27°C	1.9 l
Engine oil	10W-40	API SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)	-18°C to 27°C	1.6 l
Engine oil	15W-40	API SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)	-12°C to 38°C	1.6 l	OnaMax
Engine oil	15W-40 (OnaMax)	API Class SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)	-12°C to 38°C	1.9 l
Engine oil	SAE 30	API Class SG or SH (also SG/CD, SG/CE, SH/CD or SH/CE)	above 0°C	1.9 l	Single-grade SAE 30 oil is preferable when temperatures are consistently above freezing.
Fuel	Unleaded gasoline	Minimum octane rating (Anti-Knock Index) of 87			Do not use gasoline or additives containing methanol. Leaded gasoline may be used but increases maintenance.
Fuel	unleaded gasoline	minimum octane rating (Anti-Knock Index) of 87			Do 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

Adjusting Valve Lash adjustment

Tools: feeler gauge

Engine must be at room temperature.
Remove the valve rocker cover and spark plug.
Turn engine over until piston is at COMPRESSION TOP DEAD CENTER.
Check intake and exhaust valve lash with a feeler gauge.
Loosen locknut and turn lash adjusting screw until specified lash obtained.
Tighten locknut and recheck lash.

Choke Adjustment adjustment

Tools: 1/8 inch drill bit, wrench

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

Control Cable Adjustments adjustment

Tools: 1/8 inch drill bit, wrench

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

Normally no need to adjust engine speed. Instructions are for equipment manufacturer. Attempt only by qualified mechanic using accurate tachometer.
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.
Start engine, observing all equipment manufacturer's instructions and precautions.
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
Turn low-idle speed stop screw to obtain specified low-idle speed.
Move engine throttle link up against its stop tang and hold it there while bending tang as necessary to obtain specified high-idle speed.
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 specification may violate Federal and State safety standards.

Tools: accurate tachometer

Start engine and move throttle lever to lowest speed position.
Adjust low-idle speed stop screw on carburetor to specified low-idle speed.
Move throttle lever to highest speed position.
Loosen high-idle stop plate clamping screw and rotate plate to specified speed; retighten.
For lever controlled engines adjust lever stop screw instead.
Check full smooth movement of throttle control arm between stop positions.

Governor Arm Adjustment adjustment

⚠ Disconnect spark plug and battery negative cable before adjusting the governor.

Loosely assemble governor arm to governor shaft and start the lock nut.
Re-attach link to governor arm and carburetor; replace worn clips.
Push top of governor arm toward carburetor until it stops and hold.
Check governor spring pulls carburetor throttle to wide open.
Tighten lock nut; ensure governor shaft rotates clockwise against internal parts.
Tighten to Section 3 torque specifications.

Reconnecting and Reclamping the Choke and Throttle Cables adjustment

⚠ Accidental starting can cause severe personal injury or death.

Stop engine and disconnect spark plug and battery negative cable.
Push choke knob to full open-choke; set throttle lever to lowest speed.
Loosen cable clamp at engine bracket if necessary.
Hook cable wires into hook holes in choke and throttle control arms.
Rotate control arms clockwise, hold against stops, pull out cable slack, tighten clamp.
Check smooth movement and full travel of choke knob and throttle lever.
Reassemble air cleaner and reconnect spark plug and battery.

12 VDC Output System Tests diagnostic

⚠ Reversed battery connections or operation without a battery will damage the voltage regulator and/or alternator stator.

Tools: multimeter (Simpson 270)

Check battery voltage with engine not running; charge if out of specification.
With engine running, check voltage regulator output at battery terminals.
Disconnect stator leads from regulator and test stator AC output.
Shut down engine and check resistance between each stator lead and ground.
Check stator resistance across stator leads with ohmmeter.
Replace stator if resistance out of specification.
Replace flywheel assembly if stator resistance is correct but output low.

Air Cleaner Element Replacement maintenance

Pull choke knob to full-choke position to close choke plate.
Remove outer cover; wipe away loose dust and debris.
Remove mounting nut, inner cover and air cleaner element.
Wipe dust and debris from the air cleaner base.
Install new paper element and secure with inner cover and mounting nut.
Tighten nut 1-1/2 turns after seating it on the cover.
Reinstall foam wrapper and outer cover.

Air Cleaner Maintenance maintenance

Refer to Table 2 for scheduled foam wrapper maintenance and air cleaner element replacement. See Figure 4.
For foam wrapper only: do not remove inner air cleaner cover. Remove and wash foam wrapper in water and detergent.
Squeeze foam wrapper dry like a sponge. Rinse with clean water and allow to dry.
Coat wrapper evenly with one tablespoon (14 grams) of SAE 30 engine oil. Knead oil into wrapper and wring out excess oil.
Install foam wrapper over paper air cleaner element by stretching it over inner cover. Completely cover all exposed paper pleats.
Replace foam wrapper when it becomes torn or stretched.
For element replacement: pull choke knob to full-choke position to close choke plate. Remove outer cover and wipe away loose dust and debris.
Remove inner air cleaner mounting nut and cover.
Remove air filter paper element and foam wrapper from engine. Wipe off dust and debris from air cleaner base.
Install new paper element and secure with inner cover and mounting nut. Reinstall foam wrapper and outer cover. Reconnect crankcase breather tube.

Cooling System Maintenance maintenance

⚠ Always wear safety glasses when using compressed air or pressure washer to avoid severe eye damage.

Tools: Compressed air, Pressure washer

Wear safety glasses.
Let engine cool, especially when using pressure washer. Temperature stresses from cleaning hot engine can crack cylinder.
Use compressed air or pressure washer to clean cylinder cooling fins.
Observe all manufacturer's instructions and precautions when using pressure washer.

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.

Inspect fuel lines and fittings for leaks. Repair leaks immediately.
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.
Check engine for dirt and debris and clean flywheel air inlet screen and cylinder cooling fins as necessary.
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
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.
Reinstall dipstick and cap after checking or adding oil, turning clockwise until secure.

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 Cummins/Onan E140H?

The Cummins/Onan E140H engine has an oil capacity of 0.9 liters.

What is the displacement of the Cummins/Onan E140H?

The Cummins/Onan E140H has a displacement of 390.0 liters.

Which generators use the Cummins/Onan E140H engine?

The Cummins/Onan E140H powers 1 generator set(s), including Cummins/Onan E140.

How often should you change the oil in the Cummins/Onan E140H?

The Cummins/Onan E140H oil change interval is every 24 hours.

What is a common problem with the Cummins/Onan E140H engine?

A commonly reported issue on generators using the Cummins/Onan E140H is: Weakness and Sleepiness. Fix: Get out into fresh air immediately, shut down the unit and do not use it until it has been inspected..