How to Change the Oil in a 2018 Kawasaki KX100: A Complete Guide

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Changing the oil in your 2018 Kawasaki KX100 is essential maintenance that keeps your dirt bike running smoothly and extends its engine life. This step-by-step guide from MotoSport.com will walk you through the entire process—including the tools required, model-specific tips, and safety considerations—to make this maintenance task easy and effective even for beginners.

Tools and Materials Needed

  • 14mm socket (for drain bolt)
  • Socket wrench or ratchet
  • Measuring cup or graduated container (capable of measuring 700ml)
  • Drain pan or oil container
  • Funnel
  • Clean cloth or rag
  • Fresh transmission oil (10W-40 recommended, quantity required: 700 milliliters)
  • Gloves (optional, for cleanliness and safety)

Preparation

  • Warm up the engine by starting your KX100 and letting it idle for 1–2 minutes. This helps the old oil drain more easily and completely by thinning it out (do not rev hard; you want a gentle idle) .
  • Turn off the engine and place your bike on a stable stand so it sits upright and level.
  • Ensure you have a clear workspace and all your tools are within easy reach.

Step-by-Step Instructions

  1. Locate the Oil Drain Bolt:
    • The oil drain bolt is positioned at the bottom of your engine, typically on the left side. Use the 14mm socket to identify it .
  2. Drain the Old Oil:
    • Place your drain pan beneath the drain bolt.
    • With your socket wrench, carefully loosen and remove the drain bolt. Be cautious, as the oil may be hot.
    • Allow all the oil to drain out. You may slightly tilt the bike side-to-side to ensure a more complete drain.
    • It‘s a good practice to visually inspect the old oil for any metallic particles or discoloration, which could indicate engine or transmission wear.
  3. Replace and Tighten the Drain Bolt:
    • Once the oil has completely drained, wipe the area around the drain hole clean with a rag.
    • Reinstall the drain bolt. Do not overtighten. Use only moderate hand force; overtightening can strip the threads or crack the case .
  4. Fill with Fresh Oil:
    • Measure 700 milliliters of your chosen 10W-40 transmission oil in your graduated container .
    • Remove the filler cap (right side of the engine case, typically marked “OIL”) and place a funnel in the opening.
    • Pour in the measured oil slowly to prevent overflow or air bubbles.
    • Reinstall and tighten the filler cap by hand.
  5. Check the Oil Level:
    • Hold the bike upright, not on the stand, so it is perfectly vertical.
    • On the right side of the engine, locate the small oil level check notch in the case; the oil should be level with this mark .
    • If you cannot see oil at the notch, add very small amounts incrementally and recheck until the correct level is achieved.
  6. Clean Up and Dispose of Oil Properly:
    • Wipe any spilled oil from the engine and floor.
    • Dispose of the used oil at a proper recycling or hazardous waste facility. Never pour oil down drains or onto the ground.

Model-Specific Call-Outs for 2018 Kawasaki KX100

  • Oil capacity is exactly 700 milliliters. Overfilling can create excessive pressure and cause leaks, while underfilling risks poor lubrication .
  • The KX100 uses transmission (gear) oil, not traditional engine oil, as this two-stroke‘s engine internals are lubricated via the fuel/oil mix. Use a good-quality 10W-40 or a manufacturer-recommended gear oil .
  • Do not overtighten the green drain bolt; stripped threads on a magnesium case are expensive to repair .
  • If your KX100 is equipped with aftermarket parts (such as a skid plate), you may need to remove or loosen it for access to the drain bolt.
  • It is wise to replace the drain bolt crush washer if it is deformed, as this ensures a proper seal and prevents leaks.

Frequently Asked Questions

  • How often should I change the oil? For hard riding or racing, change the oil every 3–5 hours of run time. Trail riders or casual use can stretch changes up to 10 hours, but always consult your owner‘s manual.
  • Can I use fully synthetic oil? Yes, as long as it meets the correct viscosity and specification for gear/transmission use.
  • Does the KX100 have an oil filter? No, the 2018 KX100‘s two-stroke transmission does not utilize an oil or screen filter for the oil compartment. Regular changes are crucial.

Conclusion

Keeping up with regular oil changes on your 2018 Kawasaki KX100 is simple but critical maintenance. Following these steps and tips ensures smooth shifting, longer gearbox life, and top performance on the track or trail. For all your part and lubricant needs, visit MotoSport.com—your trusted source for dirt bike parts, tools, and expert advice.

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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.