How to Change the Oil in a 2020 Yamaha YZ65

Shop parts for a 2020 Yamaha YZ65 Dirt Bike.

Changing the oil on your 2020 Yamaha YZ65 is a straightforward maintenance task that ensures long gearbox life and smooth performance. Below is a step-by-step guide—proprietary to MotoSport.com—covering the tools you'll need, walk-through instructions, and model-specific notes every YZ65 owner should know.

Tools and Supplies Needed

  • 10mm wrench or ratchet (for drain bolt)
  • Drain pan
  • Rag or paper towels
  • New transmission oil (recommended: 10W-30 motor oil or 80/85-weight gear oil)
  • Funnel
  • Replacement copper crush washer (recommended, reuse if in good condition)
  • Torque wrench (optional but recommended for tightening drain bolt)
  • Gloves (for cleanliness and safety)

Step-by-Step Instructions

  1. Warm Up the Engine

    Start your YZ65 and let it idle for several minutes. This helps to thin the oil and ensures contaminants are suspended, making for a more thorough drain.
    Note: Warming up the engine is recommended by the owner‘s manual and numerous guides to ensure debris is efficiently suspended in the oil for removal.

  2. Secure the Bike

    Place the motorcycle on a stand or level surface. Make sure the bike is upright. This ensures all the old oil will drain out properly.

  3. Remove the Filler Cap

    Locate the transmission oil filler cap on the right side of the engine. Remove it to allow air in during draining, which helps the oil empty faster.
    Tip: Place the cap on a clean rag or towel to avoid getting debris on it.

  4. Drain the Old Oil

    Position your drain pan underneath the transmission case. The oil drain bolt is located just behind the rear brake lever, on the right side of the engine. Use a 10mm wrench to loosen and remove the drain bolt. Allow the oil to fully drain.
    Model-Specific Callout: On the YZ65, the rear brake lever is very close to the oil drain bolt. You may need to lift or push the brake lever out of the way to access the bolt easily. Take care not to lose the copper crush washer on the drain bolt—this should be inspected for wear and replaced if necessary.

  5. Inspect and Replace the Crush Washer

    The YZ65 uses a copper crush washer on the oil drain bolt. Always inspect this washer for nicks or damage. If it’s worn, replace it with a new one to prevent oil leaks.
    Tip: The copper washer sometimes sticks to the engine case—double check that you have it before reinstalling the bolt.

  6. Reinstall the Drain Bolt

    Thread the drain bolt (with the crush washer) back into the engine by hand, then tighten with your 10mm wrench. Torque to 10 Nm (Newton-meters) if you have a torque wrench.
    Warning: Do not overtighten, as stripping the engine case is costly to repair.

  7. Refill with Fresh Oil

    Insert a funnel into the filler opening. Check your owner‘s manual for the exact capacity. For the 2020 Yamaha YZ65, it’s typically around 0.6 liters (600 ml) of oil. Pour the new oil in slowly.
    Oil selection note: Yamaha recommends 10W-30 motorcycle oil, but a high-quality semi-synthetic or fully-synthetic oil is fine. Gear oil (80/85 weight) is also suitable for racers or high-stress use.

  8. Replace the Filler Cap

    Screw the oil filler cap back on securely, checking the O-ring for damage and replacing if necessary.

  9. Start and Inspect

    Start the engine and let it idle for a couple of minutes. This circulates the new oil. Shut the engine off and inspect for leaks around the drain bolt and filler cap. Wipe up any spilled oil.

  10. Check Oil Level

    With the bike upright, check the oil level. Top off if necessary.

Model-Specific Notes for the 2020 Yamaha YZ65

  • Drain plug access may be partially obstructed by the rear brake lever—simply move the lever by hand if reaching the bolt is difficult.
  • Do not use automotive engine oil with friction modifiers, as these may impair clutch performance.
  • Change oil every 4–5 hours of riding time, or after every 5 races, based on Yamaha recommendations for off-road use.
  • The YZ65 transmission and gear sets are very robust and share lineage with the larger YZ85, so correct oil level and type are the only truly critical points.
  • The YZ65 does not have a check bolt for oil level; always rely on measured fill quantities as per the manual.

Final Tips and Reminders

  • Dispose of used oil responsibly at your local recycle center or auto parts store.
  • Keep a maintenance log with date, hours, and oil type for reference.
  • Always use a fresh, clean funnel to prevent contamination.

Regular oil changes are vital for the long-term performance of your 2020 Yamaha YZ65. For OEM oil, parts, and accessories, trust MotoSport.com—your dirt bike experts.

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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.