How to Change the Coolant in a 2011 Kawasaki KX85

Shop parts for a 2011 Kawasaki KX85 Dirt Bike.

If you own a 2011 Kawasaki KX85, keeping your cooling system in top condition is essential for reliability and power. Changing the coolant is a routine but often overlooked maintenance task – neglecting it can result in overheating and engine damage, especially in a high-revving two-stroke like the KX85. Follow these steps for a safe and thorough coolant change specific to your dirt bike.

What Makes the KX85 Unique?

  • The KX85 uses a compact, high-revving two-stroke engine. Keeping the coolant clean ensures maximum heat transfer and protects vital engine components, especially during aggressive riding or racing.
  • The cooling system capacity is small, so it can be sensitive to air pockets or coolant loss. Bleed the system carefully.
  • Stock radiators on the KX85 can be susceptible to damage from crashes. While performing a coolant change, inspect the radiators for bent fins or leaks.

What You Need

  • Fresh coolant – Use a high-performance motorcycle coolant compatible with aluminum parts and safe for two-strokes.
  • 10mm socket or wrench
  • Drain pan
  • Funnel
  • Gloves and eye protection
  • Clean rag

Step-by-Step Coolant Change for the 2011 Kawasaki KX85

  1. Let the engine cool: Never attempt this on a hot bike. Coolant can be extremely hot and cause serious burns.
  2. Remove the radiator cap: The cap is located on top of the left-side radiator. Loosen the cap slowly to release any pressure.
  3. Find and loosen the coolant drain bolt: Locate the drain bolt (commonly a 10mm bolt) at the bottom of the water pump cover on the right side of the engine. Place the drain pan under the bolt.
  4. Drain the old coolant: Remove the drain bolt and tilt the bike slightly to the left to ensure all coolant drains out. You may need to remove the radiator cap fully at this stage.
  5. Flush if needed: If your coolant is dirty or you're changing types (e.g., from standard green coolant to a specialized performance fluid), flush the system by running distilled water through the radiators and engine – reinstall the drain bolt and repeat the draining process. Never leave plain water in the system.
  6. Replace the drain bolt: Clean the bolt and threads, then reinstall and tighten securely. Wipe any spills from the engine and frame.
  7. Add new coolant: Using a funnel, pour new coolant into the radiator neck until full. Squeeze the radiator hoses gently to help release any trapped air bubbles.
  8. Bleed the system: With the bike on a level surface, slowly rock it side-to-side and gently squeeze the hoses again. Top off the radiator if necessary.
  9. Run the engine: With the radiator cap off, start the bike and let it idle for a few minutes. Watch for air bubbles and add coolant as needed. When stable, turn off the engine.
  10. Reinstall the radiator cap properly: Once the level stays constant and coolant stops bubbling, secure the cap.
  11. Dispose of the old coolant safely: Used coolant is toxic to people, pets, and the environment. Take it to a proper recycling or disposal facility.

Owner Tips Specific to the 2011 KX85

  • Check radiator hoses for cracks or wear while everything is apart.
  • Inspect the radiator cap for damage – a weak spring or damaged seal causes overheating.
  • Change coolant every 40-50 hours of riding or annually, whichever comes first, especially if you ride or race in muddy or sandy conditions.
  • Always use coolant rated for use in aluminum radiators to prevent corrosion.

Following this guide helps keep your 2011 Kawasaki KX85 running crisp and cool – on the track or trail. Inspect, maintain, and ride with confidence.

Related Shopping Categories

Shop Radiators for a 2011 Kawasaki KX85 Dirt Bike.

Shop Coolant for a 2011 Kawasaki KX85 Dirt Bike.

Shop Temperature Sensors for a 2011 Kawasaki KX85 Dirt Bike.

Shop Tools for a 2011 Kawasaki KX85 Dirt Bike.

Shop Radiator Hoses for a 2011 Kawasaki KX85 Dirt Bike.

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.