How to Change the Oil in a 1989 Kawasaki KX250

Shop parts for a 1989 Kawasaki KX250 Dirt Bike.

Changing the oil on your 1989 Kawasaki KX250 is essential for peak performance, clutch longevity, and extended engine life. Although the KX250 is a two-stroke—which uses oil mixed into the fuel for engine lubrication—the transmission and clutch share a separate gearbox oil system. Regular changes prevent contaminants from causing premature wear. Below are the tools, steps, tips, and model-specific notes you need for a successful oil change—proprietary to MotoSport.com.

Tools and Supplies Needed

  • Socket set (8mm and/or 12mm sockets for drain and cover bolts)
  • Ratchet
  • Torque wrench (capable of foot-pounds/ft-lbs range)
  • Funnel
  • Drain pan
  • Shop rags
  • Contact cleaner (optional for cleaning case interior)
  • Replacement oil: Motocross-specific 2-stroke transmission oil, 10W40 or as recommended by Kawasaki
  • Measuring cup or bottle with milliliter/quart markers
  • Replacement crush washer for the drain plug (recommended per service manual)
  • Owner’s manual or service manual for reference

Step-by-Step Instructions

  1. Warm up the Bike
    • Start your KX250 and let it idle for 2-3 minutes to warm the oil for easier draining. Shut off the engine before proceeding.
  2. Position the Motorcycle
    • Place the bike on a level surface and use a bike stand. This ensures a complete drain of old oil.
  3. Remove the Drain Plug
    • Locate the oil drain bolt on the bottom of the case under the engine. Use your socket to loosen and remove it, letting old oil drain into your pan. Inspect the bolt and crush washer–replace the washer if deformed or worn for proper sealing.
  4. Drain Old Oil Completely
    • Allow a few extra minutes to ensure all old oil has exited. Slightly rock the bike or tip from side to side to assist drainage.
  5. Clean the Drain Plug and Surface
    • Wipe the drain plug and underside of the case with a rag. Carefully install the plug with a new washer. Tighten by hand, then use a torque wrench to finish (recommended torque for KX transmission drain bolts is 13-18 ft-lbs; consult your manual for exact spec).
  6. Add Fresh Oil
    • Locate, remove, and set aside the oil fill cap. Using a funnel, pour in fresh transmission oil. For the 1989 KX250, the capacity is 850cc (0.85L). Stop as the oil nears the inspection/check bolt. Model callout: The right side clutch cover has a sight or level bolt–fill until the oil reaches this hole and just begins to seep out, then reinstall the bolt and cap firmly.
  7. Check for Leaks
    • Carefully clean up spilled oil. Re-check the drain and filler plugs for tightness. Start the bike and idle for a minute, shut it down, then inspect again for leaks and check oil level.

1989 Kawasaki KX250 Model-Specific Tips

  • Oil fill capacity is 850cc (0.85 L) of 2-stroke gearbox oil–overfilling can cause the clutch to slip, while underfilling can risk gear and bearing damage.
  • The fill level bolt on the right crankcase cover is a quick way to ensure correct oil volume–add oil until it begins seeping out this hole.
  • The 1989 KX250 does not have a replaceable oil filter for gearbox oil–focus on using clean oil and regular intervals.
  • Replace the crush washer on the drain bolt to avoid leaks–a common oversight.
  • If you ride in wet or muddy conditions, consider more frequent oil changes to prevent clutch wear and contaminated oil.

Oil Recommendations

  • Use a high-quality 2-stroke transmission oil rated for wet clutch use (10W30 or 10W40 if using four-stroke oil temporarily in a pinch).
  • Do not use regular automotive oils; additives can degrade clutch performance.

Final Notes from MotoSport.com

Routine oil changes on your 1989 Kawasaki KX250 mean more time riding, less time in the shop, and superior protection for the transmission and clutch. Proper tools, accurate measurement, and model-specific attention ensure flawless results every time. Ride safe.

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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.