How to Change the Coolant in a 2024 GAS GAS MC85BW

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Regular coolant changes are essential to keep your 2024 GAS GAS MC85BW engine running at optimal temperatures and to ensure long-term durability, especially during hard riding. GAS GAS has incorporated performance-focused features in the MC85BW, including advanced radiators for superior cooling, making proper coolant maintenance even more critical to support the design intent.

What Makes the 2024 GAS GAS MC85BW Special?

  • High-performance radiators designed for consistent cooling and efficient heat dissipation, especially in competitive motocross conditions.
  • Lightweight chassis and race-optimized ergonomics, meaning the bike often runs at higher loads and subject to more temperature fluctuations, highlighting the importance of a healthy cooling system.
  • Modern 2-stroke engine that demands precise thermal management to maintain peak torque and power delivery, especially given the revised engine settings and improved airbox design.

Tools & Supplies Needed

  • Metric socket set (for panels and radiator cap, typically 8mm – 10mm)
  • Drain pan or container
  • New OEM recommended coolant (preferably phosphate-free, non-silicate for motorcycle systems)
  • Funnel
  • Shop rags and gloves

Step-by-Step Guide: Changing the Coolant

  1. Preparation
    • Ensure the bike is completely cool before working on the cooling system. Hot coolant can cause severe burns.
    • Position the MC85BW securely on a stand or level surface for safe access.
  2. Remove Bodywork for Access
    • The left side panel may be easily removed without tools on the MC85, thanks to a quick-release airbox cover design, which also grants access to the radiator area.
  3. Locate the Radiator Cap and Drain Bolt
    • The radiator cap is found at the top of the left radiator. Slowly unscrew and remove it to relieve any residual pressure.
    • The coolant drain bolt is usually situated low on the water pump or side of the engine case. Place your drain pan under this bolt.
  4. Drain the Old Coolant
    • Remove the drain bolt and allow all old coolant to flow out into the drain pan. Tip the bike slightly side-to-side to assist complete drainage.
    • If equipped, open any bleed screws on the top of the radiators to aid draining.
  5. Flush the Cooling System (Recommended)
    • Briefly pour distilled water through the radiator filler neck to flush out leftover coolant or debris. Refit the drain bolt after the system is clear.
  6. Refill with New Coolant
    • Using a funnel, slowly refill the radiator with the correct volume of new coolant (refer to the owner manual for exact capacity; MC85 typically holds around 0.5L to 0.7L, but check your MMY specs).
    • Pause occasionally to let air escape.
  7. Bleed Air from the System
    • On some bikes, you may need to lean the bike or gently squeeze radiator hoses to remove air bubbles. If the MC85BW has a bleed screw, open it until coolant flows without bubbles, then close.
  8. Reinstall All Components
    • Refit the radiator cap securely.
    • Replace the side panel and any other hardware removed.
  9. Start – Check for Leaks
    • Start the engine and let it idle for a few minutes. Watch the temperature gauge (if equipped) and check for leaks at the drain bolt, radiator seams, and hoses.
    • After engine cools, recheck the coolant level and top off if necessary.

Additional Tips for 2024 MC85BW Owners

  • Inspect radiator fins for blockages, especially after muddy rides. Gently straighten any bent fins for best airflow.
  • Monitor the coolant for signs of contamination – any oil or unusual debris could indicate a potential gasket or seal issue.
  • If you regularly race or ride in extreme temps, consider more frequent coolant changes to protect your investment.

Proper coolant maintenance on your MC85BW not only preserves the performance edge built into this impressive mini motocrosser, but also safeguards against costly engine repairs. Keep the system in top shape to enjoy every lap – just as GAS GAS intended.

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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.