How to change motorcycle engine oil

Home mechanic (basic tools) · Time: 40 to 60 min (estimate) (estimate)

Oil wears out: it fills with fine metal, carbon and acid, and it gets thinner. Fresh oil protects the engine and the wet clutch. Many commuter engines have a wire-mesh strainer behind the drain cap and a centrifugal filter (a spinning drum on the crankshaft that throws dirt to its outer wall) inside the right cover. This job cleans the strainer. A centrifugal filter or a paper cartridge needs its own access, seals and torque from your manual; it is not covered here.

Safety

• Hot oil burns. Let the engine cool until you can hold your hand on the cases, but change while still warm so dirt drains out.
• Wear nitrile gloves. Used oil harms skin.
• On the K-Light the strainer screen and spring can jump out when the cap comes off. Keep your face back.
• Take used oil to a collection point. Never pour it on the ground or into drains.

You need

• Oil of the grade, type and quantity in your manual. The K-Light manual gives the quantity but not the grade; get the grade from the dealer or the label.
• A new O-ring or sealing washer for the drain cap.
• Check you have the right plug. Some engines have other plugs near the drain (for the gear stopper spring, for example). Removing the wrong one makes a mess and can damage the gearbox.
• Some engines have two drain bolts, for example older twins. Drain both.
• On some engines with a side drain bolt, a gearshift return spring bolt sits close by. Do not remove it: the spring must then be repositioned, which can mean taking the engine out of the frame. The manual shows which bolt is which.
• Draining while the engine is warm gets more of the old oil out, but very hot oil burns. Running it briefly to warm and mix the oil is enough.

Steps

1. Ride or idle for a few minutes to warm the oil, then stop the engine.
2. Put the bike upright on the centre stand on level ground. Place the tray under the drain cap.
3. Remove the filler cap or dipstick. This lets air in so the oil drains faster.
4. Undo the drain cap slowly. Catch the spring and strainer screen.
5. Let the oil drain fully. The K-Light manual also says to turn the engine over a few times with the starter to push out more old oil. Skip this unless your own manual includes it.
6. Look at the old oil and the screen. Use Inspect drained oil for clues if you see metal, water or a fuel smell.
7. Wash the screen in clean solvent or new oil. Replace it if it is torn or bent.
8. Check the spring, the cap threads and the cap seal. Fit a new O-ring or washer.
9. Refit screen, spring and cap. Tighten by hand first, then to the torque in your manual: filter spring screw cap 15 to 30 N·m (K-Light 125). Use this only on that cap; it is not a value for other plugs or covers.
10. Pour in new oil through a clean funnel: 1.1 ± 0.1 L at an oil change (K-Light 125). Pour a little less than the full amount first.
11. Refit the filler cap. Start the engine and let it idle without revving: 2 to 3 min (K-Light 125). If an oil light is fitted, it should go out within a few seconds.
12. Stop the engine, wait, and check the level with Check the engine oil level. Top up to the upper mark.
13. Look under the engine for drips around the cap.

Check your work

• Level is between the marks after settling.
• No leak at the drain cap after a short ride. If it leaks, do not just tighten harder: drain again and check the seal and threads.
• Write the date and odometer reading on a label or in the service book.
• If the oil filter was changed too, the level drops after the first run as the new filter fills. Run the engine for about a minute, let it rest for several minutes, check the level again and top up.
• Dry-sump engines: run the engine for several minutes before reading the level. See Check the oil level on a dry-sump engine.

If it did not fix the problem

• Oil turns black again within a few hundred km: Oil turns black very soon after a change.
• Metal glitter or flakes in the old oil: Metal particles or flakes in the oil.
• Drain cap drips: Oil leaking from the drain plug.

Reference values (K-Light 125)