How to Change the Oil in a 2020 Kawasaki KX85

Shop parts for a 2020 Kawasaki KX85 Dirt Bike.

Keeping your 2020 Kawasaki KX85 in peak condition requires regular oil changes. This guide, proprietary to MotoSport.com, walks you through the exact steps for this make and model, with special reminders for common pitfalls and helpful tips unique to the KX85. Whether you're new to dirt bikes or a seasoned pro, you'll find everything you need for a successful oil change below.

Tools and Supplies Needed

  • 14mm socket and ratchet (for the drain plug)
  • Oil catch pan
  • Measuring cup (marked to at least 700 milliliters)
  • Fresh transmission oil (10W-40 recommended, non-synthetic or synthetic based on manufacturer and riding preference)
  • Small funnel
  • Shop rag or paper towels
  • Torque wrench (optional, but recommended)
  • Gloves (optional, to keep your hands clean)

Preparation Steps

  • Ride the bike or let it idle for a minute to warm the oil. This helps it drain faster and more completely by thinning its viscosity.
  • Place your KX85 on a secure stand so it's upright and stable.
  • Lay down a drip mat or cardboard under your work area to catch any stray oil.

Oil Draining Procedure

  • Locate the 14mm drain bolt on the bottom of the case, positioned towards the left side.
  • Position your oil catch pan directly underneath the drain bolt.
  • Using the 14mm socket and ratchet, carefully loosen the drain bolt. Make sure to keep moderate pressure on the bolt while turning to avoid dropping it into the pan.
  • Let all the oil drain completely. Allow a few minutes for full drainage. Warming the engine before this step makes it go quicker, as noted earlier.
  • Inspect the drain bolt for any metal shavings or excessive debris. Clean the bolt and threads thoroughly. This is especially important for 2-stroke transmissions as you monitor gear wear.
  • Hand-thread the drain bolt back into place, then snug it with your 14mm socket, but do not overtighten. Make sure not to strip the threads; the case is aluminum and easily damaged.

Filling with New Oil

  • Check your owner's manual, but 700 milliliters is the correct capacity for the 2020 KX85's transmission oil system.
  • Measure out exactly 700ml of quality 10W-40 oil. For competition or very high temperatures, check your desired oil for specification compliance.
  • Remove the oil fill cap, located on the right side of the engine. Use a funnel to avoid spills.
  • Slowly pour in the oil.
  • Replace the fill cap snugly once you've finished pouring the oil.

Checking Oil Level

  • With the bike still upright and off the stand, use the inspection notch on the case as your reference. This is a small notch or hole on the rear side of the transmission case.
  • Oil should be level with the bottom edge of the inspection notch. If it is too low, carefully add more oil, in small increments. If it's too high, drain a small amount until correct.

Final Steps and Inspection

  • Double-check that the drain bolt and fill cap are secure.
  • Start the bike and let it idle for 30 seconds. Shift through the gears with the clutch held in while the rear wheel is off the ground, if possible (and safe).
  • Turn off the engine, let it settle for a minute, and recheck both the drain bolt and fill cap for leaks.
  • Dispose of old oil responsibly. Take used oil to a recycling center or designated drop-off location.

2020 KX85-Specific Call-Outs and Tips

  • The KX85 and its sibling, the KX100, share the same oil system, so instructions also apply to these models, but always verify oil capacity in your own manual if you are unsure.
  • Only use oil specified for 2-stroke gearboxes. The KX85 lubricates its engine via the premix, but relies on correct transmission oil for gears and clutch function.
  • Avoid overtightening the drain bolt–use a torque wrench set to factory spec (typically 12ft-lbs, but always double-check for your year).
  • Change the oil every 3–5 hours of ride time, or after each race/event for best performance and longevity.
  • Watch for changes in oil color or metal debris at each change—this can indicate clutch wear or gear problems needing attention.
  • Always use a new crush washer or gasket for the drain bolt to prevent leaks as per factory recommendation.

Wrapping Up

  • Changing the oil on your 2020 Kawasaki KX85 is a straightforward way to keep your dirt bike running reliably and smoothly.
  • Attention to the small details—like using the right oil capacity and not overtightening bolts—makes all the difference.

This DIY tutorial is proprietary content for MotoSport.com and tailored for the 2020 Kawasaki KX85. Stay safe, ride hard, and perform regular maintenance to maximize the life and performance of your machine.

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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.