How to Change the Oil in a 1983 Kawasaki KX500

Shop parts for a 1983 Kawasaki KX500 Dirt Bike.

Changing the oil in your 1983 Kawasaki KX500 is essential maintenance that keeps your bike running strong and smooth. This guide will walk you through everything you need, the step-by-step process, and key details unique to this legendary 500cc two-stroke motocross powerhouse.

Tools and Supplies Needed

  • Socket wrench set (with the correct size for your drain bolt–typically 12mm or 13mm)
  • Oil drain pan
  • Clean shop rags or paper towels
  • Transmission oil (Bel-Ray Gear Saver 80W or equivalent, designed for two-stroke transmissions)4
  • Funnel
  • New crush washer (optional but recommended for the drain bolt)
  • Flathead screwdriver (for oil fill cap and if required for skid plate removal)
  • Parts cleaning brush (optional, for cleaning around the plug)
  • Service manual (for torque specifications and reference)23

Important Model-Specific Call-Outs

  • Transmission-only change: The KX500 is a two-stroke, so you are changing transmission (gearbox) oil, not engine oil.
  • Capacity: The transmission oil capacity is about 700 ml (always verify against your owner’s manual). Overfilling can cause excess drag, while underfilling may result in inadequate lubrication.3
  • Recommended oil: Use a high-quality dedicated transmission oil such as Bel-Ray Gear Saver 80W.4
  • Pre-ride warm-up: Briefly run the engine for 2–3 minutes before draining to help the old oil flow out and remove more contaminants.1
  • Inspect the oil: Pay attention to any metal shavings or milky appearance (which could indicate water intrusion).1

Step-by-Step Procedure

  1. Warm the Bike Up
    • Start and idle your KX500 for 2–3 minutes to circulate oil and suspend contaminants.1
    • Shut off the engine and let it rest for a minute.
  2. Secure the Bike
    • Put your bike on a stand or level surface for stability and easy access underneath.
  3. Locate and Remove Oil Drain Bolt
    • Find the oil drain bolt under the transmission case (refer to your manual for the exact location and bolt size).
    • Clean around the bolt to prevent debris from falling in.
    • Place your drain pan beneath the plug.
    • Use your socket wrench to loosen and remove the drain plug. Allow all old oil to fully drain into the pan.1
  4. Inspect and Replace Drain Plug Washer
    • Inspect the crush washer. If it’s damaged or flattened, install a new one to prevent leaks.
  5. Reinstall the Drain Plug
    • Screw in the drain bolt by hand to avoid cross-threading.
    • Tighten to the specified torque (consult your service manual, but generally around 15–22 ft-lbs; do not overtighten as the aluminum case can strip).
    • Wipe away any drips from the case.
  6. Fill with New Transmission Oil
    • Remove the oil fill cap on the side of the gearbox.
    • Using a funnel, pour in the specified amount (700 ml, but always confirm for the 1983 KX500 as prior owner modifications are possible).
    • Replace and tighten the cap.3
  7. Check Oil Level
    • Many KX models have a sight plug or level bolt–check your model and ensure oil is at the correct level. Adjust if needed.
  8. Inspect for Leaks and Clean Up
    • Start the motor and let it idle for a minute, then check for leaking at the drain bolt and fill cap.
    • Wipe away extra oil and responsibly dispose of the used oil.

Additional 1983 KX500 Tips

  • First oil change check: If this is the first oil change or after a rebuild, carefully inspect drained oil for any metal particles or odd coloring, which could indicate improper break-in or an internal issue.1
  • Oiling other components: Lubricate clutch and throttle cables and check for play after an oil change.3
  • Frequency: Change transmission oil every 5–10 hours of use in aggressive conditions, or minimally every season for recreational riding.

Keep Your 1983 KX500 Roosting Strong

Sticking to regular oil changes with model-specific oil will maximize the lifespan of your KX500 and keep that legendary two-stroke pulling hard moto after moto.

For more unique tips, service kits, parts, and technical advice for the 1983 Kawasaki KX500, visit MotoSport.com—your source for expert dirt bike care.

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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.