How to Change the Oil in a 2018 Yamaha YZ65

Shop parts for a 2018 Yamaha YZ65 Dirt Bike.

Maintaining your Yamaha YZ65 is essential, especially when it comes to regularly changing the transmission oil. This detailed guide—proprietary to MotoSport.com—walks you through every step required to perform a professional-quality oil change on your 2018 YZ65, complete with the tools you'll need, step-by-step instructions, and essential model-specific tips.

Tools and Supplies Needed

  • 10mm box-end wrench or ratchet
  • Drain pan for used oil
  • Clean shop rags or paper towels
  • Replacement transmission oil (Yamaha recommends 10W-30 motor oil or 85-weight gear oil; approx. 0.60 L)
  • Replacement copper crush washer or gasket for drain bolt (optional but recommended)
  • Torque wrench (recommended)
  • Funnel
  • Gloves (optional for cleanliness)

Preparation

  • Warm up the engine for several minutes. This thins the oil, making it easier to drain and helping suspended debris flow out with the oil.
    Note: Some owners debate whether this stirs up debris, but Yamaha's manual recommends warming up the engine before changing the oil.
  • Turn the engine off and place the motorcycle upright on a level surface, such as a stand.

Step-by-Step Oil Change Process

  1. Remove the transmission oil filler cap.
    This is located on the right side of the engine. Removing the cap helps the oil drain out smoothly by preventing a vacuum. Set the cap and its O-ring aside on a clean towel.
  2. Place your drain pan beneath the transmission drain bolt.
    The drain bolt is located just behind the rear brake pedal on the right side of the YZ65.
  3. Loosen and remove the drain bolt with a 10mm wrench.
    As you loosen the bolt, make sure the copper washer (crush washer or gasket) comes off with the bolt. If it sticks, carefully remove it. Let the oil drain completely.
  4. While the oil is draining, inspect the crush washer.
    If it's damaged or overly compressed, replace it with a new one to prevent leaks. Many owners reuse the washer once or twice, but new is best for peace of mind.
  5. After draining stops, reinstall the drain bolt and crush washer.
    Tighten the bolt to the specified torque: 10 Nm (Newton meters). Using a torque wrench here prevents stripping the threads or under-tightening.
  6. Add fresh transmission oil.
    Using a funnel, pour in 0.60 L (600 cc) of your chosen oil (10W-30 or 85-weight gear oil). Yamaha does not use a check bolt–add exactly what the manual specifies. Overfilling or underfilling can result in poor clutch performance or gearbox damage.
  7. Reinstall the oil filler cap and its O-ring.
  8. Start the engine and let it idle for 30 seconds.
    Shut it off, wait a few minutes, then check for leaks. Tighten bolts further if necessary.
  9. Clean up any spilled oil and recycle the used oil responsibly.

2018 Yamaha YZ65 Specific Tips and Call-outs

  • The YZ65 does not use a sight glass or an oil level check bolt for the transmission; rely strictly on the correct oil volume by measuring before pouring.
  • The drain bolt location is partially obstructed by the rear brake pedal. You might need to work around the pedal for easier access.
  • Never over-tighten the drain bolt, as the aluminum threads in the crankcase can easily strip. Use a torque wrench set to 10 Nm.
  • Change the oil every 4–5 hours of riding, or sooner if you ride in race conditions or harsh environments. Clean oil significantly prolongs gear and clutch life.
  • Factory recommended oil types: Yamalube 10W-30 or any comparable quality 10W-30 motor oil, or 85-weight gear oil. Avoid using automotive engine oils with friction modifiers, as these can harm the clutch performance.

Post-Oil Change Checklist

  • Verify there are no leaks at the drain bolt or filler cap.
  • Double-check all bolts for proper tightness.
  • Record the date, hours, and type of oil used for future reference.

Changing the oil on your 2018 Yamaha YZ65 is quick, affordable, and critical for maintaining the very best clutch and gearbox performance. Always refer to the Yamaha owner’s manual for the most up-to-date recommendations and safety warnings. If you have any concerns or encounter resistance during bolt removal or installation, contact a MotoSport.com professional mechanic for personalized support. Ride safe.

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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.