Start by running the engine for a few minutes to warm up the oil. This will help it flow more easily when you drain it.
Turn off the engine and let it cool down for a few minutes.
Remove the oil filler cap/dipstick — this will help the oil drain out easier. (It should be labeled “Oil.”)
Locate the oil drain plug on the bottom of the engine.
Place a drain pan underneath the engine to catch the old oil.
Use a wrench to loosen the drain plug/sealer washer and remove it. Allow the old oil to drain completely into the pan. The oil will take approximately 5 min to drain. It may be hot so don’t play in the oil.
While the oil is draining clean the drain plug. It’s recommended to replace the sealing washer with a new one.
Once the oil has drained, replace the drain plug and tighten it securely.
Locate the oil filler cap on the top of the engine and add new oil to the engine. The Honda GX390 engine requires 1.1L (1100ml) of oil. Ensure the engine is level when filling.
Use a funnel to avoid spills and overfilling.
Replace the oil filler cap and wipe up any spills or drips.
Start the engine and let it run for a few minutes to circulate the new oil.
Check the oil level with the dipstick. Add more oil if necessary to bring it up to the proper level.
That’s it! You have successfully changed the oil on your Honda GX390 engine.
