How to Change the Coolant in a 1985 Kawasaki KX60: Complete Maintenance Guide

Shop parts for a 1985 Kawasaki KX60 Dirt Bike.

Keeping your 1985 Kawasaki KX60 running cool is crucial for performance and longevity. Regular coolant changes reduce the risk of overheating and help safeguard the iconic 60cc two-stroke engine, which is prized for its simplicity, light weight, and high-revving nature. Below is a step-by-step, MotoSport-exclusive guide to changing the coolant in your vintage KX60, along with special notes for owners of this classic mini motocross machine.

Tools & Supplies Needed

  • Socket set (8mm or 10mm, based on bolt size)
  • Phillips screwdriver (for bleeder screw, if equipped)
  • Rags
  • A container to catch old coolant
  • Fresh motorcycle coolant (avoid automotive coolants with silicates)
  • Distilled water (for flush, optional)
  • Safety gloves and eyewear

Step 1 – Preparation

  • Make sure the bike is completely cool before starting. This prevents burns and allows for complete coolant drainage.
  • Position the bike on a stable stand for easy access and stability.

Step 2 – Access and Remove Radiator Cap

  • Locate the radiator cap on the left side of the KX60's radiator. Remove the cap to release internal pressure and allow the system to drain smoothly.

Step 3 – Locate and Remove Drain Bolt

  • Find the coolant drain bolt on the water pump cover or the lower area of the right engine case (typically an 8mm or 10mm bolt).
  • Place your catch container underneath the bolt and loosen the drain bolt. Tilt the bike slightly if needed to ensure all fluid drains out.

Step 4 – Optional: Flush the Cooling System

  • If the old coolant appears dirty or rusty, pour distilled water into the radiator, replace the cap, and briefly run the bike. Turn it off, then drain the water and repeat if necessary until the system runs clear.

Step 5 – Check and Clean Components

  • Inspect the radiator cap and gasket for cracks or excessive wear—replace if necessary.
  • Wipe any residue from the filler neck and drain bolt area before reassembly.

Step 6 – Reinstall Drain Bolt

  • Reinstall the drain bolt by hand to avoid thread damage, then snug it with your socket. Do not overtighten. For best results, use a new crush washer if the old one is deformed.

Step 7 – Fill with New Coolant

  • Slowly pour in fresh motorcycle coolant until the radiator is full. Avoid overfilling; leave a small air gap at the top.
  • If your KX60 has a small bleed screw on the opposite radiator side, loosen it briefly while filling to let trapped air escape, then tighten again as coolant begins to seep out.

Step 8 – Bleed and Top Off the System

  • With the radiator cap off, start the engine and let it idle several minutes. Watch for any bubbling as remaining air purges from the system.
  • Shut off the engine, let it settle, and check coolant level. Top off as needed. Replace the radiator cap, ensuring it clicks past the safety stop.

Step 9 – Clean Up and Inspect for Leaks

  • Use a rag to wipe down any spilled coolant. Inspect the area around the drain bolt and the radiator for leaks before your next ride.

Special Notes for 1985 KX60 Owners

  • The KX60 uses an air-cooled head with radiator-based liquid cooling for the case and cylinder. Maintaining correct coolant type and volume is key to avoiding seizure or piston scuffing in these high-revving engines.
  • Be gentle with all cap and bolt threads, as aluminum threads on vintage bikes can strip easily.
  • Check the radiator regularly for fin damage or blockage, which is common on older bikes used off-road.
  • Avoid using tap water when mixing coolant—only distilled water prevents mineral buildup in your small-cavity system.

Disposal Tips

  • Never pour old coolant down the drain. Take used coolant to a recycling center or hazardous waste collection site.

Changing the coolant regularly on your 1985 Kawasaki KX60 will keep it running cool and fast for years to come, whether you're preserving its race heritage or introducing the next generation to the joys of two-stroke riding.

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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.