Facts About Generators
GeneratorsDirectoryCompareRepairEnginesControllersPartsManufacturersGuides
Search models or part #
Home›Engines›Mitsubishi EH25-2D

Mitsubishi EH25-2D Engine

The Mitsubishi EH25-2D is an engine. It powers generator sets from Cummins/Onan, including the RGV4100. It holds 1 L (0.3 gal) of oil.

Also known as: Mitsubishi Heavy Industries EH25-2D

1.0 L
Oil capacity
On this pageSpecsGenerator setsFAQService intervalsTorque & specsFluidsProcedures

Engine specifications

Oil capacity1.0 L

Common problems

2
  • When No Electricity Is Generated at Receptacle :
    Fix: Check to make sure no-fuse breaker is in the "ON" position. Check AC and DC terminals for loose connection. Check to see if engine starting was attempted with appliances already connected to generator. After making sure that the total wattage of the electrical appliance is within permissible limits and there are no defects in the appliance, turn the no-fuse breaker to the "ON" position. If breakers continue to actuate, consult your nearest servicing dealer. Secure connection if necessary. Turn off switch on the appliance, and disconnect cable from receptacle. Reconnect after generator has been started properly.
  • When Engine Fails to Start :
    Fix: Check if choke lever is in its proper position. Check if fuel cock is open. Check fuel level. Check to make sure generator is not connected to an appliance. Check spark plug for loose spark plug cap. Check spark plug for contamination. Check if engine switch is in OFF. Set the choke lever to "CLOSE" position. If closed, open fuel cock. If empty, refill fuel tank making sure not to overfill. If connected, turn off the power switch on the connected appliance and unplug. If loose, push spark plug cap back into place. Remove spark plug and clean electrode. Turn engine switch to ON.

Compiled from service & troubleshooting documentation across every generator set that uses the Mitsubishi EH25-2D.

Service intervals

12
ItemActionHoursMonthsNotes
air cleaner elementClean50 hrDaily inspection: clean air cleaner element
bolts and nutsCheck8 hrEvery 8 hours (Daily)
engineCheck8 hrDaily inspection: excessive vibration, noise
engine oilCheck8 hrRefill daily up to upper level (Daily)
fuel and oil leakageCheck8 hrDaily inspection: leakage of gasoline and engine oil
gasolineCheck8 hrDaily inspection: enough gasoline
generatorClean8 hrEvery 8 hours (Daily)
surroundingsCheck8 hrDaily inspection: safe surroundings
engine oilChange100 hrFirst service — Thereafter change oil every hundred (100) hours
spark arresterClean100 hrClean spark arrester every hundred (100) hours
air cleaner elementReplace200 hrReplace element set every 200 hours
fuel linesReplace1000 hr12 moReplace the fuel hose every 1,000 hours or every year

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

4
TypeItemValueUnitCondition
GapSpark plug electrode gap0.02 to 0.03 in. (0.6 to 0.7 mm)
GapSpark plug electrode gap0.03 in. (0.7 to 0.8 mm)
Valve clearanceValve clearance (Intake and Exhaust)0.0039±0.0006 in (0.1±0.015 mm)cold
Valve clearanceValve clearance (Intake and Exhaust)0.0039±0.0012 in (0.1±0.03 mm)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-40API service class SE or higher grade (SG, SH or SJ is recommended)If single viscosity oil is used, select the appropriate viscosity for the average temperature in your area. Oil capacity: RGV2800 0.65 liter; RGV4100 1.0 liter; PX6100/e 1.2 liter.
FuelAutomotive 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

⚠ Death, personal injury and/or property damage may occur unless instructions are followed carefully.

  1. Use battery of recommended capacity (12V-24AH or larger).
  2. Turn the starter switch to the STOP position when mounting or dismounting battery.
  3. When mounting battery, connect the positive (+) cable first and then the negative (-) cable to the battery.
  4. When dismounting battery, disconnect negative (-) cable first.
  5. Tighten bolts and nuts on terminals securely so they will not be loosened by vibration.
  6. Disconnect battery cables when charging battery.
Connecting to Domestic Circuits (House Wiring) installation

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

⚠ A transfer switch must be installed by a certified/licensed electrician to transfer the load from the commercial power source to the generator.

  1. When connecting a generator to a house wiring, generator output power must be taken from the 240V-4P receptacle.
  2. Install a transfer switch.
  3. If the neutral wire of house wiring is grounded, be sure to ground the ground terminal of the generator.
  4. Set the full power switch to 120V/240V side.
  5. Turn the house AC breaker off before starting the generator.
  6. Start the generator and warm it up.
  7. Turn the house AC breaker on.
Cleaning Air Cleaner (RGV2800) maintenance
  1. Unhook the cover and remove the cleaner element.
  2. Inner element: Wash the element with kerosene, then soak it in mixed oil (Kerosene 3 parts : Engine oil 1 part). Drain the mixed oil.
  3. Outer element: Wash the element with kerosene, then dip it into the mixed oil (Kerosene 3 parts : Engine oil 1 part). Squeeze out the mixed oil (Do not twist).
Cleaning Air Cleaner (RGV4100, PX6100) maintenance

⚠ Do not wash elements with kerosene, gasoline or oil.

  1. Urethane Foam Element: Wash and clean the urethane foam with detergent. After cleaning, dry it. Clean every 50 hours.
  2. Paper element: Clean by tapping gently to remove dirt and blow off dust. Never use oil. Clean every 50 hours and replace element set every 200 hours.
Cleaning Fuel Strainer maintenance

⚠ Gasoline is flammable.

  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: plug cleaner, wire brush

  1. If the plug is contaminated with carbon, remove it using a plug cleaner or wire brush.
  2. Adjust the electrode gap.
Engine Oil Change maintenance

⚠ Change engine oil every 100 hours. For new engine, change oil after 20 hours.

  1. Drain oil by removing the drain plug and the oil filler cap while the engine is warm.
  2. Reinstall the drain plug and fill the engine with oil until it reaches the upper level on the oil filler cap.
  3. Use fresh and high quality lubricating oil to the specified level.
Fuel Hose Replacement maintenance

⚠ Take extreme caution when replacing fuel hose; gasoline is flammable.

  1. Replace the fuel hose every 1,000 hours or every year.
  2. If fuel hose leak is found, replace the fuel hose immediately.
Preparation for Storage maintenance

⚠ NEVER USE WATER TO CLEAN GENERATOR!

  1. Drain fuel from fuel tank carefully by disconnecting the fuel line.
  2. Remove the carburetor float chamber and also drain the carburetor.
  3. Change engine oil.
  4. Check for loose bolts and screws, tighten them if necessary.
  5. Clean generator thoroughly with oiled cloth. Spray with preservative if available. NEVER USE WATER TO CLEAN GENERATOR!
  6. Pull starter handle until resistance is felt, leaving handle in that position.
  7. Store generator in a well ventilated, low humidity area.
Idle Control Switch Operation operation
  1. Start the engine with IDLE CONTROL SWITCH off.
  2. Warm up the engine without a load for a few minutes.
  3. Turn IDLE CONTROL SWITCH on.
  4. The switch automatically reduces engine speed when load is OFF, and automatically increases engine speed to rated r.p.m. when load is ON.
  5. Turn IDLE CONTROL SWITCH off when it does not work normally under the rated output.
Starting the Engine operation

⚠ Do not run the starting motor over 5 seconds continuously.

  1. Turn the engine switch to the ON position (Recoil starter model only).
  2. Turn the no-fuse breaker to the OFF position.
  3. Open the fuel cock.
  4. Pull the choke knob to close if the engine is cold.
  5. Recoil starter model: Pull the starter handle slowly until resistance is felt, then return and pull swiftly.
  6. Electric starter model: Insert the key and turn it clockwise to the RUN position, then further to START.
  7. Do not run the starting motor over 5 seconds continuously; wait about 10 seconds then start again.
  8. After the engine starts, return the choke knob gradually to OPEN position.
  9. Warm up the engine without a load for a few minutes.
Stopping the Generator operation
  1. Turn off the power switch of the electric equipment and unplug the cord from the receptacle.
  2. Turn the no-fuse breaker to the OFF position.
  3. Allow the engine about 3 minutes to cool down at no-load before stopping.
  4. Recoil starter model: Turn the engine switch to the OFF position.
  5. Electric starter model: Turn the key switch to the STOP position.
  6. Close the fuel cock.

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 Mitsubishi EH25-2D?

The Mitsubishi EH25-2D engine has an oil capacity of 1.0 liters.

Which generators use the Mitsubishi EH25-2D engine?

The Mitsubishi EH25-2D powers 1 generator set(s), including Cummins/Onan RGV4100.

What is a common problem with the Mitsubishi EH25-2D engine?

A commonly reported issue on generators using the Mitsubishi EH25-2D is: When No Electricity Is Generated at Receptacle :. Fix: Check to make sure no-fuse breaker is in the "ON" position. Check AC and DC terminals for loose connection. Check to see if engine starting was attempted with appliances already connected to generator. After making sure that the total wattage of the electrical appliance is within permissible limits and there are no defects in the appliance, turn the no-fuse breaker to the "ON" position. If breakers continue to actuate, consult your nearest servicing dealer. Secure connection if necessary. Turn off switch on the appliance, and disconnect cable from receptacle. Reconnect after generator has been started properly..