How to Change the Oil in a 1987 Kawasaki KX500

Shop parts for a 1987 Kawasaki KX500 Dirt Bike.

Changing the gearbox oil in your 1987 Kawasaki KX500 is a crucial maintenance task that keeps your two-stroke’s transmission running smoothly and extends its lifespan. This robust guide, proprietary to MotoSport.com, walks you through every step, lists specific tools needed, and flags known KX500 quirks every owner should know before getting their hands oily.

Tools and Supplies Needed

  • Socket wrench set (Metric, preferably with 17mm and 19mm sockets)
  • Oil drain pan
  • Clean rags or shop towels
  • Funnel
  • Replacement crush washer (for the drain bolt, optional but recommended)
  • Gearbox oil (Consult your service manual; commonly 10W-40 or dedicated 2-stroke gearbox oil)
  • Torque wrench (for proper drain bolt tightness)
  • Gloves and safety glasses

Preparation and Safety Notes

  • Always warm the bike up briefly before changing the oil; warm oil drains more thoroughly.
  • Ensure the engine is off and cool enough to avoid burns.
  • Work in a well-ventilated area away from open flames or sources of sparks.

Step-by-Step Oil Change Procedure

  • Place the bike upright:– Use a bike stand to ensure the KX500 is level. This helps all the old oil flow out and you refill with the correct amount.
  • Locate the drain plug:– On the 1987 KX500, the drain bolt sits at the bottom of the right engine case, just beneath the shift lever.
  • Position the oil pan:– Slide your pan directly under the drain plug to avoid spills.
  • Remove the drain plug:– Loosen with your socket wrench (turn counter-clockwise). Keep pressure as you remove it to prevent it falling into the pan. Be careful—the oil may still be warm.
  • Check the oil for debris:– Let the oil drain fully. Inspect for any metallic shavings, which could signal engine issues, though in a routinely maintained KX500, you should see little to none, even after years of hard riding.
  • Inspect the drain plug and washer:– Replace the crush washer if it's deformed or shows wear. Clean any residue from the plug and surrounding areas.
  • Reinstall the drain plug:– Hand-tighten, then use a torque wrench to tighten to the manufacturer’s specification (typically about 14 ft-lbs/20 Nm–check your service manual to confirm). Do not over-tighten to avoid stripping the threads.
  • Remove the oil fill cap:– It’s usually on top of the right side cover.
  • Add new oil:– Use a funnel for accuracy. The KX500 typically takes about 650 cc (0.65 L) of oil, but check your owner’s manual for specifics. Slowly pour in the new oil to avoid overfilling.
  • Replace the fill cap:– Tighten by hand until snug.
  • Start the engine and check for leaks:– Idle for a minute, then shut off. Wipe around the drain bolt and check for seepage. If you see any leaks, recheck the bolt tightness (do not overtighten).
  • Check oil level:– Some KX500 models have a sight glass; others require measuring the drained amount and filling with the same. Adjust as needed.
  • Dispose of old oil:– Take it to a designated oil recycling center—never dump it in the trash or on the ground.

Model-Specific Call-Outs for 1987 KX500

  • The KX500 gearbox is separate from the two-stroke engine oil system–it requires regular changes as the clutch and transmission shear oil more rapidly under performance use.
  • Early KX500s (1983-1989) use similar drain/fill configurations as later models, but always confirm bolt locations and torque settings; years outside your manual’s range may differ. Gearbox capacity for 1987 is typically 650 cc.
  • Always inspect the old oil for signs of excessive clutch debris or metal shavings. Any shiny flecks may indicate abnormal wear–routine for a hard-ridden KX500 but worth monitoring.
  • Replace the crush washer every other change to prevent leaks, as aging washers on these older models easily deform.
  • If the bike is new to you or this is the first oil change in a while, consider changing the oil after every few rides for the first interval to clear out old residues from years of storage.

Tips for Getting the Most From Your 1987 KX500

  • Use high-quality, non-friction-modified gearbox oils specifically designed for two-stroke transmissions for optimal clutch feel and gearbox longevity.
  • Keep oil change intervals short: every 5-10 hours of use, or after every race.
  • If you ride in muddy or wet conditions, consider changing your oil more frequently, as contamination accelerates oil breakdown.
  • Don’t overtighten any bolts—older aluminum cases are prone to stripping if over-torqued.

Regular maintenance is the key to keeping your 1987 Kawasaki KX500 at peak performance mile after mile. MotoSport.com is your destination for quality oils, filters, and parts to keep your legend alive.

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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.