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.
Maintenance schedule
| Item | Spec | Capacity | Part # | Interval | |
|---|
| Air filter | Replace air filter as needed for best engine performance. | | — | 300 hr | |
| Fuel filter | Clean | | — | 50 hr | |
| Oil filter | Check | | — | 3 hr | |
| Battery | Check-adjust | | — | 300 hr | |
| Belt | Replace | | — | 100 hr | |
| Coolant | Check-adjust | | — | 500 hr | |
| Oil | 1.4 US gal (5.3 L) | 1.4 US gal | — | 2800 hr | |
| Spark plug | Replace | | — | 500 hr | |
Pooled from every document that names this exact engine — confirm the interval and part number against your unit's serial number.
Procedures
12Air Cleaner Service maintenance
⚠ Never use gasoline or low flash point solvents to clean the element.
⚠ Never run the generator without the air cleaner.
- Remove wing nut and air cleaner cover; remove and separate elements.
- Check both elements for holes or tears; replace if damaged.
- Foam element: wash, rinse and dry thoroughly, soak in clean engine oil, squeeze out excess.
- 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.
- Drain oil while engine is still warm.
- Remove drain plug and filler cap, drain oil, retighten plug securely.
- Refill with recommended oil and check level.
Engine Oil Change maintenance
⚠ Wash hands with soap after handling used oil.
- Remove drain plug and sealing washer, remove oil filler cap, and drain oil.
- Reinstall drain plug and sealing washer. Tighten securely.
- Refill with recommended oil and check oil level.
Fuel Sediment Cup Cleaning maintenance
- Turn fuel valve OFF. Remove sediment cup, O-ring, and filter.
- Clean sediment cup, O-ring, and filter in nonflammable solvent.
- Reinstall filter, O-ring, and sediment cup.
- 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.
- Check engine on a level surface with engine stopped.
- Remove oil filler cap and wipe dipstick clean.
- Insert dipstick into oil filler neck but do not screw it in.
- 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.
- Check the fuel level.
- If low, fill to the shoulder of the fuel filter.
- Close filler cap securely.
Sediment Cup Cleaning maintenance
- Turn the fuel valve to OFF.
- Remove the sediment cup and O-ring and wash in nonflammable solvent.
- Dry thoroughly and reinstall securely.
- 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
- Remove eight 5 mm screws from muffler protector and remove protector.
- Remove 4 mm screw from spark arrester and remove it from muffler.
- Use a brush to remove carbon deposits from the arrester screen.
- 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
- Remove spark plug cap and use spark plug wrench to remove plug.
- Visually inspect plug; discard if insulator cracked or chipped.
- Measure plug gap with feeler gauge.
- Check washer condition and thread plug in by hand.
- 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.
- Ensure storage area is free of excessive humidity and dust.
- Drain fuel: remove and empty sediment cup with fuel valve OFF.
- Turn fuel valve ON and drain tank into suitable container.
- Replace sediment cup and tighten securely.
- Loosen carburetor drain screw and drain gasoline.
- Change the engine oil.
- Remove spark plug, pour about a tablespoon of clean engine oil into cylinder, crank several revolutions, reinstall plug.
- 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.
- Drain carburetor by loosening drain screw into suitable container.
- Change engine oil.
- Remove spark plug, pour about a tablespoon of clean engine oil into cylinder. Crank engine several revolutions, reinstall spark plug.
- Slowly pull starter grip until resistance is felt.
Starting the Engine operation
⚠ Do not allow starter grip to snap back against the engine.
- Make sure AC circuit breaker is OFF.
- Turn fuel valve to ON.
- Move choke lever to CLOSE (do not use choke if engine is warm).
- Turn engine switch to ON.
- Pull starter grip lightly until resistance felt, then pull briskly.
- 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.
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.