How to Change the Oil in a 2018 Yamaha TTR125L: Step-by-Step Guide

Shop parts for a 2018 Yamaha TTR125L Dirt Bike.

Changing the oil in your 2018 Yamaha TTR125L is a straightforward maintenance task every rider should know. Routine oil changes keep your engine running smoothly and extend the life of your bike. This guide, proprietary to MotoSport.com, will walk you through the tools required, detailed steps, and model-specific nuances for the TTR125L.

Tools and Supplies Needed

  • 10mm or 17mm socket and ratchet (Check your bike's drain bolt size; usually 17mm for the TTR125L)
  • Oil drain pan
  • Funnel
  • Clean rags or shop towels
  • New engine oil (Yamaha recommends Yamalube 4-stroke oil, consult your manual for viscosity and capacity)
  • New crush washer for the drain bolt (recommended to replace each oil change)
  • Gloves (optional, to keep oil off your hands)

Step-by-Step Instructions

  1. Warm up the engine.
    • Start the bike and let it idle for a few minutes. Warm oil will drain faster and more completely.
  2. Secure the bike.
    • Place the bike on the kickstand. The TTR125L–s drain bolt is on the left side, so the bike–s natural tilt helps oil drain efficiently. A rear stand is optional but not required.
    • Engage first gear and consider tying the front brake for extra stability. Make sure the surface is level.
  3. Locate and remove the drain bolt.
    • The drain bolt is easily accessible on the left side of the engine by the footpeg (“waffles” on the engine case) for the TTR125L, not the bottom like many bikes. This makes draining the oil much easier.
    • Place the oil drain pan underneath, and loosen the drain bolt with your socket wrench. Avoid losing the crush washer.
  4. Drain the old oil.
    • Let the oil fully drain into the pan. If the bike was properly warmed up, this should only take a few minutes.
    • To help expel old oil, you can gently “kick” the engine over a few times by hand (with the kill switch off and transmission in neutral).
  5. Check and clean the drain bolt and washer.
    • Wipe off the bolt and inspect the threads. Replace the crush washer with a new one to prevent leaks (as recommended in Yamaha–s documentation).
  6. Reinstall the drain bolt.
    • Thread the bolt back in by hand to avoid cross-threading. Tighten gently with the socket and ratchet—just snug. Do not overtighten—the engine case is soft aluminum and overtightening can easily strip the threads or break the bolt. You–ll feel resistance when the washer seats.
  7. Remove the oil filler cap and add new oil.
    • The filler cap is above the left-side engine cover and doubles as a dipstick. Remove it and insert a funnel.
    • Pour in the recommended quantity and type of oil. For the TTR125L, Yamaha states the specific oil amount on the engine case. This is approximately 0.9 – 1.0 liter, but always verify with your owner–s manual and the stamp on your actual engine. Pour slowly and avoid overfilling.
  8. Check the oil level.
    • With the bike upright and level (not on the kickstand), insert the dipstick but do not screw it in. Remove it and check the oil level—it should be between the minimum and maximum marks.
    • Add small amounts of oil and recheck as needed until the level is correct.
  9. Start the engine and inspect.
    • Start the engine and let it idle for a minute. Check around the drain bolt for leaks. Turn off the engine and let it sit for a couple minutes.
    • Recheck the oil level and top off if necessary. Install the dipstick/filler cap securely.
  10. Dispose of the used oil responsibly.
    • Take your used oil to an approved recycling collection center or automotive store.

Special Notes for the 2018 Yamaha TTR125L

  • Drain Bolt Location: Unique to the TTR125 series, the drain bolt is on the left side near the footpeg, not on the bottom. This makes changes less prone to messes and easier for DIY oil changes.
  • Oil Volume Stamp: Yamaha conveniently stamps the recommended oil quantity directly on the left engine case. On the TTR125L, it‘s easy to find and read near the filler cap.
  • Crush Washer: Don‘t skip replacing the crush washer during every change. It‘s inexpensive and prevents leaks or stripped threads.
  • Routine Oil Checks: For optimal performance, check your oil before every ride, not just after oil changes.
  • Dipstick Technique: Always check the oil level with the dipstick resting in the threads, not screwed in.

Conclusion

Changing the oil on your 2018 Yamaha TTR125L is simple and can be done with basic tools at home. Following these steps ensures you keep your TTR125L in peak running condition for years of reliable off-road fun. For OEM Yamaha parts and premium oils, trust MotoSport.com for all your dirt bike maintenance needs.

Happy riding and wrenching.

<.-- Content sourced and adapted from direct model-specific instructions and best-practice tips for TTR125L oil changes . -->

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Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.