How to Change the Coolant in a 2010 Kawasaki KX85: Step-by-Step Guide

Shop parts for a 2010 Kawasaki KX85 Dirt Bike.

Keeping your 2010 Kawasaki KX85 running cool ensures optimal performance and engine longevity, especially during intense moto sessions. Coolant should be changed regularlytypically every 40 to 50 hours of riding or at the start of each season for most riders.

Tools – Supplies Needed

  • Quality motorcycle coolant (never use plain water)
  • 10mm socket or wrench
  • Drain pan
  • Funnel
  • Shop rags
  • New crush washer for coolant drain bolt (recommended)
  • Compressed air (optional for complete flush)

Step 1: Preparation

  • Ensure the engine is completely cool before starting to avoid burns from hot coolant.
  • Place the bike securely on a stand and remove the radiator cap to release system pressure.

Step 2: Locate and Remove the Coolant Drain Bolt

  • Locate the coolant drain bolt on the right side of the cylinder near the bottom. Place your drain pan under this area.
  • Use the 10mm wrench to loosen and remove the drain bolt. Coolant will begin to flow out.
  • Pro tip: Tilting the bike gently to the left will encourage full drainage.
  • Inspect the crush washer on the drain bolt—replace it if needed to ensure a proper seal during reassembly.

Step 3: Drain the System Completely

  • Allow the coolant to finish draining from the system. You may squeeze the lower radiator hoses to help force trapped coolant out.
  • For a more thorough flush, you may remove the lower radiator hose and use compressed air to blow residual coolant from the system. Ensure no debris or water enters the radiators during this process.

Step 4: Reinstall the Drain Bolt

  • Wipe the area around the drain hole with a shop rag.
  • Install a new crush washer on the drain bolt and tighten it securely, but do not overtighten.

Step 5: Fill with Fresh Coolant

  • Insert a funnel in the radiator fill neck.
  • Slowly pour in new high-quality coolant until it reaches just below the base of the filler neck.
  • Gently rock the bike side to side to burp air bubbles from the system.
  • Replace the radiator cap, ensuring it clicks and locks securely.

Step 6: Bleed Air and Check Levels

  • Start the bike and let it idle for several minutes.
  • Watch for bubbles appearing in the radiator or overflow tank, which indicate air is purging from the system.
  • After the engine cools again, re-check coolant levels and top off as needed.

Model-Specific Notes for the 2010 KX85

  • The KX85 features a compact, high-revving two-stroke enginekeeping this engine cool is even more critical for power retention and longevity.
  • Utilize only dirt bike-appropriate coolants that resist cavitation and provide freeze and corrosion protection in aluminum radiators.
  • Always inspect radiator hoses and clamps for signs of wear or bulging during coolant changes. Replace any questionable parts proactively to prevent mid-ride failures.
  • Monitor the radiator cap gasket for splits or stiffness, as a worn cap can lead to overheating and pressure loss.

Aftercare and Maintenance Tip

  • Ride the bike at moderate speed for a few minutes, then allow it to cool before a final coolant level check. This ensures all air is expelled.
  • Check coolant level again after your next ride, as minor settling or air purge can occur.

By following these steps, you’ll keep your 2010 Kawasaki KX85 in peak operating condition all season long, whether chasing checkered flags or exploring the trails.

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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.