How to Change the Coolant in a 2020 KTM 150XCW TPI

Shop parts for a 2020 KTM 150XCW TPI Dirt Bike.

The 2020 KTM 150XCW TPI is celebrated for its lightweight agility, precision fuel-injection system, and exceptional trail performance. Regular coolant maintenance is vital–not just for optimal cooling but also to protect the advanced two-stroke engine from overheating and corrosion. Owners should note that the TPI system runs hotter and cleaner than carbureted models, making fresh, properly mixed coolant essential for long-term reliability. Below is a proprietary MotoSport step-by-step guide tailored specifically for the 2020 KTM 150XCW TPI.

What You Need:

  • Fresh coolant (meeting KTM specifications)
  • Socket set or box wrench (usually 8mm)
  • Drain pan
  • Rags or paper towels
  • Funnel
  • Optional: new drain bolt washer

Step 1: Prepare Your Bike

  • Start with a completely cool engine. Never open the radiator cap or hoses with a hot engine to avoid burns from pressurized coolant.
  • Position the bike upright on a stable stand.

Step 2: Remove the Radiator Cap

  • Locate the radiator cap on the left side of the bike. Slowly twist off the cap to release any residual pressure.

Step 3: Locate & Remove the Drain Bolt

  • On the 2020 KTM 150XCW TPI, the coolant drain bolt is typically positioned at the lower cylinder water jacket or water pump cover.
  • Hold a drain pan under the bolt, then remove it with the correct socket.
  • Let the old coolant fully drain out.

Step 4: Drain Both Radiators

  • Wait for coolant to drain from both radiators. The radiators are connected in parallel, allowing simultaneous emptying. Make sure both sides are empty before proceeding.

Step 5: Inspect & Replace Washer

  • Check the drain bolt washer for signs of wear or flattening. Replace it if needed to ensure a secure, leak-free seal.

Step 6: Reinstall the Drain Bolt

  • Clean the drain bolt and threading area with a rag.
  • Reinstall the bolt and torque it to spec. Do not overtighten–snug is adequate.

Step 7: Fill with New Coolant

  • Using a funnel, slowly pour fresh coolant into the radiator until it reaches the base of the filler neck.
  • Gently rock the bike side-to-side several times to help dislodge trapped air pockets.

Step 8: Bleed Trapped Air

  • For the 2020 KTM 150XCW TPI, it is recommended to briefly loosen the temperature sensor on the cylinder head (referred to as a thermostat in some manuals) as you add coolant. This allows air to escape from the system and ensures complete coolant fill throughout the cylinder and radiators.Important: Retighten it securely after bleeding.

Step 9: Top Off & Reinstall Radiator Cap

  • Continue topping off coolant if needed. The level should reach the bottom of the radiator cap neck but no higher.
  • Securely reinstall the radiator cap.

Step 10: Warm Up & Check for Leaks

  • Start the engine and let it idle for several minutes. Keep a close eye on coolant level and check under the bike for leaks at the drain bolt, hoses, and around the sensor.
  • Shut down, allow to cool, and recheck coolant level. Top off if necessary.

Notes & Pro Tips for 2020 KTM 150XCW TPI Owners

  • Mix Ratio: Always use coolant that complies with KTM requirements. Avoid mixing different coolant types (red and green) to prevent gel formation and system blockages.
  • Electrolysis Prevention: The TPI system's electrical components mean it is crucial to use coolant with anti-corrosion and anti-cavitation properties.
  • Coolant Change Interval: Check coolant at regular service intervals and replace at least once per season, or after any overheating event or contamination.
  • Special Precaution: Removing the temp sensor for air bleeding is a factory recommendation for this engine family. This step prevents overheating and possible engine damage by minimizing hot spots or vapor pockets. Never skip it.

Taking the time to follow these steps will keep your KTM's high-strung engine performing at its best–and help ensure you never get stranded with an overheated bike deep in the woods.

Related Shopping Categories

Shop Radiators for a 2020 KTM 150XCW TPI Dirt Bike.

Shop Coolant for a 2020 KTM 150XCW TPI Dirt Bike.

Shop Temperature Sensors for a 2020 KTM 150XCW TPI Dirt Bike.

Shop Tools for a 2020 KTM 150XCW TPI Dirt Bike.

Shop Radiator Hoses for a 2020 KTM 150XCW TPI 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.