How to Change the Oil in a 2015 Kawasaki KX85 – A Complete Guide

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Changing the oil in your 2015 Kawasaki KX85 is a crucial maintenance step to keep your dirt bike’s transmission running smoothly. The KX85 is a two-stroke machine, and like all two-strokes, it uses transmission oil (sometimes called gear oil) in the engine case, rather than sharing oil with the combustion chamber as in four-stroke bikes. Regular oil changes protect gears, clutch plates, and bearings, ensuring top performance and longevity.

Tools and Supplies Needed

  • 14mm socket and ratchet (for drain bolt)
  • Measuring cup (marked for 700 milliliters)
  • Funnel
  • Drain pan (to catch old oil)
  • Clean rag (for any spills and to wipe plug)
  • Replacement oil: 10W-40 motorcycle transmission oil or recommended gear oil (confirm with owner's manual)
  • Protective gloves (optional for cleanliness)

Step-by-Step Instructions

  1. Warm Up the Engine: Start and idle the bike for about one minute. This warms up the oil, helping it flow out more quickly and thoroughly.
    (Never rev the engine hard–just idle.)
  2. Prepare the Bike: Turn off the engine and place the KX85 on a level stand, keeping it upright and steady. This ensures accurate oil draining and refilling.
  3. Locate and Remove the Drain Plug: The drain bolt is found under the engine case. Use your 14mm socket and ratchet.
    • Position your drain pan under the drain bolt to catch the oil.
    • Loosen and remove the drain bolt carefully. Allow the oil to completely drain into the pan. (Be cautious–warm oil may flow quickly.)
    Tip: Be careful not to drop the bolt into the oil pan.
  4. Inspect and Clean the Drain Plug: Before reinstalling, inspect the drain plug for any metal shavings which could indicate gearbox wear. Wipe the plug and surrounding area clean.
    KX85-Specific Call-Out: Be careful not to overtighten the drain bolt when reinstalling, as stripping threads in the aluminum case is easy on these bikes.
  5. Reinstall the Drain Plug: Once all oil has drained, replace the drain bolt and tighten with your 14mm socket.
    • Do NOT overtighten. Just snug is sufficient–the case threads can easily strip.
  6. Measure and Add New Oil: The 2015 Kawasaki KX85 requires 700 milliliters of oil.
    • Measure out 700 ml of fresh oil using your measuring cup.
    • Pour in the oil through the oil fill cap using a funnel to avoid spills.
    Use high-quality 10W-40 transmission/gear oil or check your owner's manual for your preferred brand.
  7. Check Oil Level: With the bike level (not on side stand), verify the oil is at the proper level.
    • There is a small notch or inspection point at the fill hole. The oil should reach just up to this notch.
    • Add oil slowly if you are short, but never overfill.
  8. Start and Inspect: Start the bike and let it idle for a minute, then shut it off. Recheck around the drain plug and fill cap for leaks. Wipe up any spilled oil.
  9. Dispose of Old Oil Properly: Always recycle used oil at an appropriate facility–never pour it down drains or onto the ground.

KX85 Model-Specific Tips

  • Oil Type: The KX85 technically uses transmission/gear oil–many owners use 10W-40 motorcycle oil or purpose-specified gear oil per Kawasaki recommendations.
  • Oil Volume: 700 milliliters–do not overfill as excess oil can lead to clutch drag and shifting issues.
  • Drain Bolt Caution: The KX85 (and most small-bore Kawasakis) have relatively soft aluminum cases–do NOT overtighten the drain bolt to avoid stripping the threads.
  • Change Interval: For aggressive or race use, change the oil every 3–5 hours of riding. For lighter duty, you can extend intervals slightly, but fresh oil is cheap insurance.

Additional Owner Advice

  • Keep a log of your oil changes and operating hours–this not only helps with maintenance but also adds value at resale.
  • Always inspect old oil for metallic flakes, a key early indicator of abnormal internal wear in the transmission.
  • Use a clean, well-marked container or graduated cup: too little or too much oil can both cause performance or reliability issues.
  • Replace the crush washer on the drain bolt periodically to ensure a leak-free seal.

With these steps and a little attention to detail, keeping your 2015 Kawasaki KX85’s oil fresh is an easy DIY task that will pay off in performance and reliability on every ride.

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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.