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Honda GX240K1 Engine

The Honda GX240K1 is a 0.38 L 1-cylinder non-california type (an type) engine rated at 3600 rpm. It powers generator sets from Honda, including the EG3500X. It holds 1.2 L (0.3 gal) of oil.

Also known as: Honda GX240K1

0.38 L
Displacement
1
Cylinders
3600 rpm
Rated speed
1.2 L
Oil capacity

Engine specifications

Oil capacity1.2 L
Displacement0.38 L
Cylinders1
AspirationNon-California type (AN type)
Rated speed3600 rpm

Common problems

2
  • Engine will not start
    Cause: Engine switch is off
    Fix: Turn the engine switch on
  • Engine starts but stops immediately
    Cause: Oil alert lamp flashes when the starter is pulled (low engine oil level)
    Fix: Check the engine oil level and fill with the recommended oil; re-start the engine

Compiled from service & troubleshooting documentation across every generator set that uses the Honda GX240K1.

Maintenance schedule

ItemSpecCapacityPart #Interval
Air filterReplace air filter as needed for best engine performance.—300 hr
Fuel filterClean—50 hr
Oil filterCheck—3 hr
BatteryCheck-adjust—300 hr
BeltReplace—100 hr
CoolantCheck-adjust—500 hr
Oil1.4 US gal (5.3 L)1.4 US gal—2800 hr
Spark plugReplace—500 hr

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

Service intervals

11
ItemActionHoursMonthsNotes
Engine oilChange100 hr6 moFirst service — First month or 20 Hrs.
Air cleanerClean50 hr3 moService more frequently when used in dusty areas. (1)
Sediment CupClean100 hr6 mo
Spark arresterClean100 hr6 mo
Spark plugClean100 hr6 moClean-Adjust
Fuel tank and filterClean300 hr12 mo(1)
Idle speedAdjust300 hr12 moClean-Adjust. (2)
Spark plugReplace300 hr12 mo
Valve clearanceAdjust300 hr12 moCheck-Adjust. (2)
Combustion chamberClean500 hrAfter every 500 Hrs. (2)
Fuel tubeCheck24 moEvery 2 years (Replace if necessary) (2)

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

11
TypeItemValueUnitCondition
GapSpark plug gap0.028-0.031in
GapSpark plug gap0.028-0.031 in (0.70-0.80 mm)in (mm)
GapSpark plug gap0.7-0.8mm
OtherEngine oil capacity1.1lrefill
OtherEngine oil capacity1.2 US qt (1.1 L, 1.0 Imp qt)US qt (L, Imp qt)
OtherFuel tank capacity1.59 US gal (6.0 L, 1.32 Imp gal)US gal (L, Imp gal)
OtherFuel tank capacity6.0l
SpeedEngine max. output speed3600rpmmax. output 8.0 HP
SpeedMax. torque speed2500rpm1.7 kg-m (12.3 ft-lb)
Valve clearanceValve clearance EX0.20 ± 0.02 mmmmcold
Valve clearanceValve clearance IN0.15 ± 0.02 mmmmcold

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-30API SJ1.1 LRecommended for general, all-temperature use. Other viscosities shown in chart may be used when average temperature is within indicated range.
Engine oilSAE 10W-40 (recommended for general all-temperature use); other viscosities per ambient temperature chartSE or SF (U.S. automobile manufacturer's Service Classification)1.1 lUse Honda 4-stroke oil or equivalent high detergent premium quality motor oil; non-detergent and vegetable oils not recommended
FuelRegular grade automotive gasoline (unleaded preferred), pump octane rating 88 or higher6.0 lNever use oil/gasoline mixture or dirty gasoline. Gasohol: max 10% ethanol; max 5% methanol with cosolvents and corrosion inhibitors
FuelUnleaded gasolinePump octane rating of 86 or higher6.0 LThis engine is certified to operate on unleaded gasoline. Oxygenated fuels: up to 10% ethanol, 15% MTBE, 5% methanol with cosolvents and corrosion inhibitors.

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
Air Cleaner Service maintenance

⚠ Never use gasoline or low flash point solvents to clean the element.

⚠ Never run the generator without the air cleaner.

  1. Remove wing nut and air cleaner cover; remove and separate elements.
  2. Check both elements for holes or tears; replace if damaged.
  3. Foam element: wash, rinse and dry thoroughly, soak in clean engine oil, squeeze out excess.
  4. Paper element: tap lightly on hard surface or blow compressed air from inside out.
Changing Oil maintenance

⚠ Used motor oil may cause skin cancer if repeatedly left in contact with skin.

  1. Drain oil while engine is still warm.
  2. Remove drain plug and filler cap, drain oil, retighten plug securely.
  3. Refill with recommended oil and check level.
Engine Oil Change maintenance

⚠ Wash hands with soap after handling used oil.

  1. Remove drain plug and sealing washer, remove oil filler cap, and drain oil.
  2. Reinstall drain plug and sealing washer. Tighten securely.
  3. Refill with recommended oil and check oil level.
Fuel Sediment Cup Cleaning maintenance
  1. Turn fuel valve OFF. Remove sediment cup, O-ring, and filter.
  2. Clean sediment cup, O-ring, and filter in nonflammable solvent.
  3. Reinstall filter, O-ring, and sediment cup.
  4. Turn fuel valve ON and check for leaks.
Pre-operation Engine Oil Check maintenance

⚠ Running the engine with insufficient oil can cause serious engine damage.

  1. Check engine on a level surface with engine stopped.
  2. Remove oil filler cap and wipe dipstick clean.
  3. Insert dipstick into oil filler neck but do not screw it in.
  4. If level is low, fill to top of oil filler neck.
Refueling maintenance

⚠ Gasoline is extremely flammable and explosive; refuel with engine stopped in a well ventilated area.

⚠ Do not smoke or allow flames or sparks.

⚠ Do not overfill; wipe up spilled fuel before starting.

  1. Check the fuel level.
  2. If low, fill to the shoulder of the fuel filter.
  3. Close filler cap securely.
Sediment Cup Cleaning maintenance
  1. Turn the fuel valve to OFF.
  2. Remove the sediment cup and O-ring and wash in nonflammable solvent.
  3. Dry thoroughly and reinstall securely.
  4. Turn fuel valve ON and check for leaks.
Spark Arrester Maintenance maintenance

⚠ Allow muffler to cool before proceeding.

⚠ Be careful not to damage the spark arrester screen.

Tools: brush

  1. Remove eight 5 mm screws from muffler protector and remove protector.
  2. Remove 4 mm screw from spark arrester and remove it from muffler.
  3. Use a brush to remove carbon deposits from the arrester screen.
  4. Install arrester and muffler in reverse order of disassembly.
Spark Plug Service maintenance

⚠ Muffler will be very hot if engine has been running.

⚠ Never use a spark plug of incorrect heat range.

Tools: spark plug wrench, feeler gauge, wire brush

  1. Remove spark plug cap and use spark plug wrench to remove plug.
  2. Visually inspect plug; discard if insulator cracked or chipped.
  3. Measure plug gap with feeler gauge.
  4. Check washer condition and thread plug in by hand.
  5. Tighten with spark plug wrench to compress washer.
Storage Preparation maintenance

⚠ Turn engine switch and oil alert switch OFF and keep generator level when transporting.

  1. Ensure storage area is free of excessive humidity and dust.
  2. Drain fuel: remove and empty sediment cup with fuel valve OFF.
  3. Turn fuel valve ON and drain tank into suitable container.
  4. Replace sediment cup and tighten securely.
  5. Loosen carburetor drain screw and drain gasoline.
  6. Change the engine oil.
  7. Remove spark plug, pour about a tablespoon of clean engine oil into cylinder, crank several revolutions, reinstall plug.
  8. Pull starter rope slowly until notch on pulley aligns with hole on recoil starter, then cover engine.
Storage Procedure maintenance

⚠ Gasoline is extremely flammable. Perform in well-ventilated area with engine stopped.

  1. Drain carburetor by loosening drain screw into suitable container.
  2. Change engine oil.
  3. Remove spark plug, pour about a tablespoon of clean engine oil into cylinder. Crank engine several revolutions, reinstall spark plug.
  4. Slowly pull starter grip until resistance is felt.
Starting the Engine operation

⚠ Do not allow starter grip to snap back against the engine.

  1. Make sure AC circuit breaker is OFF.
  2. Turn fuel valve to ON.
  3. Move choke lever to CLOSE (do not use choke if engine is warm).
  4. Turn engine switch to ON.
  5. Pull starter grip lightly until resistance felt, then pull briskly.
  6. As engine warms up, gently turn choke lever to OPEN.

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

Aftermarket parts that fit this engine

3

Parts listed by aftermarket suppliers as fitting this engine — leads compiled from supplier catalogs; verify the exact part for your serial number.

Common questions

What is the oil capacity of the Honda GX240K1?

The Honda GX240K1 engine has an oil capacity of 1.2 liters.

What is the displacement of the Honda GX240K1?

The Honda GX240K1 has a displacement of 0.38 liters with 1 cylinders.

Which generators use the Honda GX240K1 engine?

The Honda GX240K1 powers 1 generator set(s), including Honda EG3500X.

How often should you change the oil in the Honda GX240K1?

The Honda GX240K1 oil change interval is every 2800 hours.

What is a common problem with the Honda GX240K1 engine?

A commonly reported issue on generators using the Honda GX240K1 is: Engine will not start. Cause: Engine switch is off. Fix: Turn the engine switch on.