How to Change the Coolant in a 2017 Cobra CX50FWE: MotoSport Guide

Shop parts for a 2017 Cobra CX50FWE Dirt Bike.

The 2017 Cobra CX50FWE is a championship-proven mini motocross machine, engineered for peak youth performance. Keeping its cooling system properly serviced is critical to both engine longevity and optimal track performance. Follow this proprietary MotoSport guide for a complete coolant change on your CX50FWE and keep your bike running cool lap after lap.

Why Changing Coolant Matters on the CX50FWE

Dirt bikes like the CX50FWE operate at high engine temperatures and are often pushed hard by young riders. Over time, coolant breaks down, losing its effectiveness in heat transfer and corrosion protection. Regular changes help prevent overheating, protect the magnesium engine cases, and ensure the mini's advanced engine stays race-ready.

Tools – What You Need

  • Fresh, high-quality motorcycle coolant (avoid automotive antifreeze)
  • Drain pan
  • Socket set or screwdriver (as needed for shrouds or radiator cap)
  • Clean rags
  • Distilled water for rinsing (if flushing the system)

Step-By-Step Coolant Change Guide

  1. Ensure the bike is cool and stable.
    Place the CX50FWE on a stand and allow the engine to cool to avoid burns from hot coolant.
  2. Remove bodywork if needed.
    Depending on access, you may need to remove the left-side shroud to reach the radiator cap and drain.
  3. Open the radiator cap.
    Locate the radiator cap on top of the left side of the bike. Open it slowly to relieve any pressure.
  4. Drain the old coolant.
    Position a drain pan under the water pump drain bolt (always check for its exact location – typically on the lower part of the engine or water pump cover). Remove the bolt and allow coolant to flow out completely. If equipped, also drain the overflow/expansion tank by disconnecting its hose at the lowest point.
  5. Inspect the system.
    Check radiator hoses for cracks, inspect hose clamps for tightness, and look for any damage to the radiator fins. Tighten or repair as needed.
  6. Flush the system (optional, but recommended).
    If your coolant is severely dirty or contaminated, fill the system with distilled water, run the engine briefly, then drain again to clear debris or residues.
  7. Reinstall the drain bolt securely.
    Always use the correct torque specification if available for your model, or hand-tighten snugly to avoid leaks.
  8. Fill with new coolant.
    Slowly fill the radiator with fresh coolant up to just below the filler neck. If an overflow tank is present, fill it to the correct level indicated.
  9. Bleed the cooling system.
    With the radiator cap off, start the bike and let it idle. Gently rock the bike side to side and rev briefly to help air bubbles escape. Top off coolant if the level drops.
  10. Replace the radiator cap.
    Once no more bubbles appear and the coolant level is steady, install the radiator cap securely.
  11. Reinstall bodywork.
    Reattach any shrouds or panels removed for access.
  12. Final check – test run.
    Run the bike until it reaches operating temperature, then allow it to fully cool. Recheck and top off coolant as necessary.

Important Notes for CX50FWE Owners

  • The CX50FWE uses premium materials like magnesium in its engine cases, which are sensitive to silicate levels. Always use a silicate-free, motorcycle-specific coolant.
  • Frequent off-road use can introduce debris into the radiator fins. Inspect and clean them during each coolant service.
  • Overheating or repeated loss of coolant may indicate a failing water pump, cracked hose, or radiator cap issues. Address any ongoing loss promptly.
  • If you spot milky or contaminated coolant, this may indicate a mechanical issue such as a failed gasket—consult a professional for repairs.

Proper Disposal

Old coolant is toxic and harmful to pets and the environment. Collect it in a sealed container and take it to a recycling center or approved automotive service location.

Related Shopping Categories

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Shop Radiator Hoses for a 2017 Cobra CX50FWE 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.