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Cummins/Onan EH65D Engine

The Cummins/Onan EH65D is a 0.65 L 2-cylinder air-cooled engine. It powers generator sets from Cummins/Onan, including the PX12000e and RGV12 CSA_US_GU2001. It holds 1.55 L (0.4 gal) of oil.

Also known as: Cummins EH65D

0.653 L
Displacement
2
Cylinders
1.55 L
Oil capacity

Engine specifications

Oil capacity1.55 L
Displacement0.653 L
Cylinders2
AspirationAir-cooled

Generator sets powered by this engine

2
Cummins/Onan PX12000eCummins/Onan RGV12 CSA_US_GU2001

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

Common problems

1
  • Generator engine fails to start after several attempts, or if no electricity is available at the output receptacles
    Cause: Possible causes include: Low battery; Blown fuse; Deteriorated fuel; Fuel piping clogging; Clogging of Air cleaner; Clogging of Cooling air intake; Low oil level; Faulty spark plug; Overload by connected appliance; Incorrect or poor connection of wires; Insufficient capacity of extension cable; Starter won't run; Leakage

Compiled from service & troubleshooting documentation across every generator set that uses the Cummins/Onan EH65D.

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filter—50 hr
Fuel filter—
Oil filter—20 hr
BatteryLead-acid battery : A capacity of 12V-32A・h or larger. For the generators used in low temperature (below -5℃), 12V-40A・h or larger battery is recommended.—500 hr
Belt—
Coolant—
OilAPI service class SE or higher grade (SG, SH or SJ is recommended)1.55 liters—20 hr
Spark plug—200 hr

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

Service intervals

9
ItemActionHoursMonthsNotes
Engine oilCheck8 hrDaily; refill daily to upper level
Generator (clean) and bolts and nutsClean8 hrDaily; also check bolts and nuts
Engine oilChange20 hrFirst service — Initial change after first 20 hours; thereafter every 100 hours per schedule Note 1 (HOW-TO Maintenance section states every 50 hours)
Engine oil filterReplace20 hrFirst service — Initial replacement after 20 hours; thereafter every 200 hours
Air cleanerClean50 hrClean or replace urethane foam and paper element every 50 hours (more often in dusty environments)
Spark arresterClean100 hrClean spark arrester every 100 hours
Air cleaner elementReplace200 hr12 moReplace element set every 200 hours or once a year
Carbon brushesReplace500 hrCheck and replace carbon brushes; check every 500 hours or if generator performance is irregular
Fuel linesReplace1000 hr12 moYearly (also every 1,000 hours per HOW-TO Maintenance)

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

5
TypeItemValueUnitCondition
ClearanceCarbon brush wear limit5 mm (0.2 in.)mmreplace brush if 5 mm (0.2 in.) long or less
GapSpark plug electrode gap0.03 in. (0.7-0.8 mm)
TorqueSpark plug tightening torque25 to 30 Nm (19 to 22 lbs/ft)
TorqueWheel mounting bolt tightening torque20 to 25 Nm (19 to 22 lbs/ft)
Valve clearanceValve clearance (intake & exhaust)0.0039±0.0008 in. (0.1±0.02 mm)engine cold

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 10W-30 or 10W-40 (multigrade); single grade 5W, 10W, 20W, #20, #30, #40 per ambient temperature4-stroke automotive detergent oil, API service class SE or higher (SG, SH or SJ recommended)1.55 litersOil capacity 1.55 liters (upper level) = 1.6 quarts
FuelUnleaded automotive gasoline, minimum octane rating RON87 or higher44.0 litersFuel tank capacity 44 liters; engine is certified to operate on automotive unleaded gasoline

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
Battery Installation installation

⚠ Disconnect battery cables when charging battery.

⚠ Turn the starter switch to the STOP position when mounting or dismounting battery.

⚠ Connect positive (+) terminal first when mounting, disconnect negative (-) terminal first when dismounting.

  1. Attach terminals to a lead-acid battery already charged and mount it with its terminals facing inward.
  2. Insert each long bolt through the specified hole, its tip pointing outward.
  3. Put the supporting arm on the long bolts and tighten with the butterfly nuts.
  4. Arrange the wiring so that it won't be damaged by engine vibration.
  5. With the starter key in the OFF position, connect the red cable to the positive (+) terminal, then the other cable to the negative (-) terminal.
Connecting to Domestic Circuit (House Wiring) installation

⚠ All connections must be made by a licensed electrician.

⚠ Failure in connection may result in death, personal injury, damage to generator, damage to appliances, damage to building's wiring or fire.

⚠ Do not connect the generator to a commercial power line.

  1. When connecting the generator to house wiring, take generator output power from the 240V-4P receptacle.
  2. Install a transfer switch of the correct capacity between the meter and the fuse or AC breaker box.
  3. If the neutral wire of house wiring is grounded, be sure to ground the ground terminal of the generator.
  4. Turn the house AC breaker off before starting the generator.
  5. Start the generator and warm it up, then turn the house AC breaker on.
How-To Install the Wheel installation

Tools: Hoist or square bar (4 in by 4 in, length 27.6 in), Plier, Spanner or socket wrench (12mm), 2 units

  1. Raise the generator by about 4 inches with a hoist or with a square bar put under the bottom panel.
  2. Attach wheel mounting parts, stopper and wheel to the wheel shaft using the clamp; check the wheel rotates smoothly (use grease if needed).
  3. Bend the tip of the part according to the shape of the wheel shaft as possible.
  4. Attach the assembled shaft to the foundation plate of the engine.
  5. Attach the other shaft to the foundation plate of the generating unit.
Checking Carbon Brush maintenance
  1. Remove the brush cover.
  2. Disconnect the wire connector and remove the brush.
  3. Replace the brush with a new one if it is 5 mm (0.2 in.) long or less.
  4. Note the brush direction and relative position with the slip ring and install the new brush correctly.
Cleaning Fuel Strainer maintenance

⚠ Gasoline is flammable; do not smoke or use open flame.

  1. Remove the strainer cup and throw away water and dirt.
  2. Clean the screen and strainer cup with gasoline.
  3. Tightly fasten the cup to main body, making sure to avoid fuel leak.
Cleaning and Adjusting Spark Plug maintenance

Tools: supplied plug wrench and handle

  1. Unplug the high-voltage cables.
  2. Using the supplied plug wrench and handle, turn the plug counterclockwise until it comes off.
  3. Clean the area around the mounting hole and clean the electrodes if dirty.
  4. Adjust the clearance to 0.03 in. (0.7-0.8 mm); replace the plug if the projection is worn flat.
  5. Attach and tighten the plug to 25 to 30 Nm (19 to 22 lbs/ft).
  6. Check the plug cap contact area for corrosion and connect the high-voltage cables.
Engine Oil Change maintenance

⚠ Check for a suitable way to dispose of old oil; do not pour into sewage drains, garden soil or open streams.

  1. Stop the engine and place generator on a stable and level surface.
  2. Loosen the drain plug and drain the oil.
  3. Re-install the drain plug before refilling oil.
  4. Refill with recommended oil to the upper level.
Engine Oil Filter Replacement maintenance

⚠ Pay attention to spilled hot engine oil when replacing the engine oil filter.

Tools: wrench

  1. Drain the engine oil.
  2. Apply oil to the new oil filter O-ring.
  3. Attach the oil filter in position and tighten 2/3 turns by hand or with wrench after the O-ring touches the sealing surface.
  4. Run the engine for a minute, stop the engine and check for oil leakage around the oil filter.
  5. Recheck the oil level.
Preparation for Storage maintenance

⚠ NEVER USE WATER TO CLEAN GENERATOR.

  1. Drain fuel from fuel tank and strainer cup carefully by disconnecting the fuel line.
  2. Run the engine at no-load until it stops to remove fuel in the carburetor.
  3. Disconnect the terminal of the battery.
  4. Change engine oil.
  5. Check for loose bolts and screws, tighten them if necessary.
  6. Clean generator thoroughly with oiled cloth; never use water to clean generator.
  7. Store generator in a well ventilated, low humidity area.
Servicing Air Cleaner maintenance
  1. Remove the knob and air cleaner cover.
  2. Remove the paper inner element and urethane foam outer element.
  3. Wash and clean the urethane foam in kerosene; saturate in 3 parts kerosene and 1 part engine oil, then squeeze out excess oil.
  4. Clean the paper element by tapping gently to remove dirt and blowing off dust; never use oil.
  5. Set the elements on the air cleaner base with the grommet in position and install the cover with knob tightened securely.
Spark Arrester Removal and Cleaning maintenance

⚠ Always use the product with a spark arrester.

⚠ If the engine has been running, the muffler and spark arrester will be very hot; allow the muffler to cool before cleaning.

Tools: brush

  1. Remove the flange bolts from the muffler cover and remove the muffler cover.
  2. Remove the special screw from the spark arrester and remove the spark arrester from the muffler.
  3. Use a brush to remove carbon deposits from the spark arrester screen; avoid damaging the screen.
  4. Replace the spark arrester if it is damaged (must be free of breaks and holes).
  5. Install the spark arrester and muffler protector in the reverse order of disassembly.
Starting the Engine operation

⚠ Do not start the generator with electrical appliances connected and switched on.

  1. Check the oil level before each operation and perform the specified Daily Inspection.
  2. Make sure that the no-fuse breaker is off.
  3. Turn the fuel cock to the vertical (open) position.
  4. Turn the starter switch to the START position.
  5. If the engine won't start, turn the switch back to ON and wait approximately 10 seconds before trying again.
  6. Warm the engine up for a minute or two before connecting loads.

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
240VSingle-phase4P receptacle (X)(Y)(G)(W) for connection to house wiring via transfer switchX, Y, W, GGenerator is neutral grounded type; use transfer switch between meter and fuse or AC breaker box

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 EH65D?

The Cummins/Onan EH65D engine has an oil capacity of 1.55 liters.

What is the displacement of the Cummins/Onan EH65D?

The Cummins/Onan EH65D has a displacement of 0.653 liters with 2 cylinders.

Which generators use the Cummins/Onan EH65D engine?

The Cummins/Onan EH65D powers 2 generator set(s), including Cummins/Onan PX12000e, Cummins/Onan RGV12 CSA_US_GU2001.

How often should you change the oil in the Cummins/Onan EH65D?

The Cummins/Onan EH65D oil change interval is every 20 hours.

What is a common problem with the Cummins/Onan EH65D engine?

A commonly reported issue on generators using the Cummins/Onan EH65D is: Generator engine fails to start after several attempts, or if no electricity is available at the output receptacles. Cause: Possible causes include: Low battery; Blown fuse; Deteriorated fuel; Fuel piping clogging; Clogging of Air cleaner; Clogging of Cooling air intake; Low oil level; Faulty spark plug; Overload by connected appliance; Incorrect or poor connection of wires; Insufficient capacity of extension cable; Starter won't run; Leakage.