How to Change the Coolant in a 2009 Kawasaki KX85

Shop parts for a 2009 Kawasaki KX85 Dirt Bike.

Keeping your 2009 Kawasaki KX85's cooling system in top shape is key to reliable performance on and off the track. Routine coolant changes help prevent engine overheating and corrosion. Use this MotoSport-exclusive guide to change the coolant in your KX85 – no copy-paste from generic guides – and keep your bike running cool all season.

What You Need

  • Fresh dirt bike-specific coolant (avoid automotive coolants that may harm aluminum components)
  • 10mm socket or wrench
  • Large Phillips screwdriver
  • Drip pan for old coolant
  • Cleansing rag
  • Small funnel
  • Gloves and safety glasses

Notes for KX85 Owners

  • The KX85's high-revving, liquid-cooled engine demands regular coolant checks – inspect and replace at least every 40-50 hours of operation or once per season under heavy use.
  • Never open a hot radiator. Let the bike cool completely to prevent burns.
  • The KX85 uses a straightforward two-radiator setup and has a dedicated coolant drain bolt on the water pump cover for easy servicing.

Step-by-Step Coolant Change Instructions

  1. Prep the Bike
    Ensure the engine is cool and the KX85 is securely upright, preferably on a stand. Remove both side panels if they hinder access to the radiator cap.
  2. Remove the Radiator Cap
    With a rag handy for any drips, twist off the radiator cap, located at the upper left radiator tank. This relieves any residual system pressure.
  3. Locate & Remove the Drain Bolt
    Place your drip pan underneath the right crankcase area. Find the coolant drain bolt (typically the lowest, forward-facing bolt on the water pump cover). Use your 10mm socket to remove this bolt and allow old coolant to drain fully.
    *Optional:* For a more thorough flush, gently lean the bike side-to-side to expel remaining fluid or remove the lower radiator hose temporarily.
  4. Inspect the Coolant & System
    Examine the drained coolant for signs of oil or debris, which may signal engine issues. Now is a great time to check radiator hoses and clamps for cracks or leaks.
  5. Reinstall the Drain Bolt
    Once drained, securely reinstall the drain bolt – do not overtighten.
  6. Refill with Fresh Coolant
    Insert a small funnel in the radiator fill neck and slowly pour in coolant until near the top. The total system capacity is about 0.45L, but always check the level visually.
    Tip: For most KX85s, using a pre-mixed, silicate-free, phosphate-free coolant formulated for aluminum engines is recommended to prevent internal deposits and corrosion.
  7. Bleed the Cooling System
    To purge air: briefly tilt the bike left and right and squeeze the radiator hoses by hand. Top off coolant if needed.
    If equipped, loosen the small bleeder screw (atop the opposite radiator) with your Phillips screwdriver until coolant drips out steadily, then retighten.
  8. Reinstall Cap & Check for Leaks
    Firmly reinstall the radiator cap. Start the bike and let it idle for several minutes. Shut it off and, once cool, recheck coolant level and inspect for leaks around hoses and the drain bolt.

KX85 Model-Specific Tips

  • Frequent coolant checks are essential, especially after muddy rides, due to the bike's compact radiators and tendency to pack with debris.
  • If your KX85 consistently loses coolant or overheats, inspect both radiators for bent fins, leaks, or blockages and consider a full system flush.
  • Always dispose of used coolant responsibly; it is toxic and must not be poured down drains or onto the ground.

Keeping your 2009 Kawasaki KX85's cooling system maintained not only extends engine life but improves reliability for every gate drop and trail ride. Stay ahead of engine troubles by making coolant service part of your regular maintenance, using only parts and supplies trusted by riders at MotoSport.

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Shop Radiator Hoses for a 2009 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.