How to Change the Coolant in a 2025 Husqvarna TC125

Shop parts for a 2025 Husqvarna TC125 Dirt Bike.

Changing the coolant on your 2025 Husqvarna TC125 is a vital maintenance task that keeps your engine running cool and ensures consistent, high-performance riding. This guide, built exclusively for MotoSport riders, walks you through the process step-by-step and highlights unique aspects of the 2025 TC125 that every owner should know.

Key Tools & Materials

  • Fresh, approved coolant (consult your owner’s manual for type recommendations)
  • Basic metric hand tools (sockets, ratchet, drain pan)
  • Clean shop towels
  • Funnel
  • Protective gloves

Preparation

  • Ensure the bike is completely cool before starting.
  • Place the motorcycle upright and stable, preferably on a stand.
  • Clean any dirt or debris from the radiator area.

Step 1: Locate the Coolant Drain Bolt

On the 2025 TC125, the coolant drain bolt is typically found on the water pump housing, on the lower right side of the engine case. If uncertain, trace the radiator hoses until you spot the lowest mounting point—this is often the optimal drain location.

Step 2: Drain the Old Coolant

  • Place a drain pan beneath the drain bolt or lowest hose connection.
  • Slowly remove the radiator cap to relieve system pressure.
  • Use the appropriate socket to loosen the drain bolt or the hose clamp on the lowest radiator hose.
  • Allow the coolant to fully drain. Slightly tilting the bike may help remove stubborn fluid.

Step 3: Flush the System (Optional but Recommended)

  • Reinstall the drain bolt or hose and secure it.
  • Fill the radiator with distilled water.
  • Run the engine for one or two minutes, then repeat the drain procedure to clear any contaminants.

Step 4: Refill with Fresh Coolant

  • Confirm the drain bolt or hose is secured and tight.
  • Using a funnel, pour coolant into the radiator until it reaches the full mark.
  • Give the radiator a light shake or gently tap hoses to dislodge air bubbles.
  • Top up as needed, then install the radiator cap securely.

Step 5: Final System Check

  • Start the engine and let it idle for several minutes with the radiator cap on.
  • Check for leaks around the drain bolt, hoses, and radiator cap.
  • After cooling, recheck fluid level and top off if necessary.

What’s Unique About the 2025 TC125?

  • This model features a lightweight, high-revving 125cc 2-stroke with innovative electronic exhaust control, built for peak performance in competition environments.
  • Use only compatible coolants—mixing types (such as silicate-based with organic acid technology) can compromise engine protection especially around the aluminum cylinder and advanced DS clutch components.
  • The 2025 design improves centralization of engine mass, so always ensure cooling system integrity after every service to maximize both performance & chassis handling benefits.†

For best results, always follow scheduled maintenance intervals provided in your owner’s manual and replace coolant at least once per year, or more frequently if racing under extreme conditions. Proper coolant care is the simplest way to protect your TC125’s industry-leading performance and reliability.

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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.