How to Change the Coolant in a 2025 GAS GAS MC 150

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Changing the coolant in your 2025 GAS GAS MC 150 is fundamental for peak engine performance and longevity. This two-stroke, liquid-cooled dirt bike features a single-cylinder 143.99 cc engine, meaning proper cooling is essential to handle demanding rides and avoid overheating issues.–4–

Before You Start

  • Make sure the engine is completely cool to avoid injury.
  • Place your bike on a stable stand.
  • Prepare a catch pan for old coolant.
  • Have fresh, recommended coolant on hand.
  • Keep a clean rag nearby for spills and a 10mm socket for most drain bolts.

Step-by-Step Coolant Change Guide

  1. Remove the Skid Plate (if equipped):
    If your MC 150 has a skid plate, remove it for easy access to the water pump and drain bolt.
  2. Open the Radiator Cap:
    Slowly twist off the radiator cap. This relieves pressure and allows coolant to drain quickly.–2–
  3. Drain the Old Coolant:
    Locate the coolant drain bolt on the lower part of the water pump cover (typically on the right side of the engine case). Place the catch pan beneath and use your 10mm socket to loosen and remove the drain bolt.
    Allow the coolant to fully drain. Check the old coolant for debris—contamination can indicate internal wear.–2–
  4. Flush the System (Optional but Recommended):
    Replace the drain bolt and fill the radiator with distilled water. Run the engine briefly (not enough to warm up), then repeat the drain procedure. This removes residual old coolant and contaminants.
  5. Reinstall the Drain Bolt:
    Ensure the sealing washer is in good condition. Tighten the drain bolt to manufacturer specs (do not overtighten).
  6. Fill with New Coolant:
    Use high-quality, premixed coolant designed for aluminum engines. Pour coolant into the radiator neck until it is nearly full.
  7. Bleed the Cooling System:
    The MC 150 cylinder head features a small bleeder port. Loosen the bleeder screw while filling the radiator and allow air to escape until coolant flows without bubbles, then retighten.–1–
  8. Top Off and Reinstall the Cap:
    Make sure the coolant level reaches the bottom of the radiator neck. Install and secure the radiator cap.
  9. Check for Leaks:
    Start the bike and let it idle until warm. Check all connections—look for leaks at the drain bolt and radiator. After cooling, recheck coolant level and top off if needed.
  10. Dispose of Old Coolant Responsibly:
    Used coolant is toxic. Take it to a proper recycling center.

Key MC 150 Model Notes

  • The liquid-cooled system is optimized for intense off-road use. Debris can clog radiators faster during muddy rides, so inspect and clean your radiators when changing coolant.–4–
  • Always bleed air from the cylinder head bleeder port. Air in the system will cause overheating and engine damage.–1–
  • Use only compatible, non-silicate, motorcycle-specific coolant to prevent corrosion in the aluminum cooling system.–4–

Maintenance Tip

Check your manual for specific torque specs and coolant type recommendations. Regular coolant changes ensure your 2025 GAS GAS MC 150 remains reliable for every race and ride.–5–

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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.