How to Change the Coolant in a 2023 KTM 350XCFW

Shop parts for a 2023 KTM 350XCFW Dirt Bike.

Changing the coolant on your 2023 KTM 350XCFW is essential for keeping the engine running cool under the harshest conditions. The process is straightforward but, as with all modern KTM engines, there are a few model-specific factors to keep in mind for a successful, air-free coolant system. Follow this MotoSport-exclusive guide for a reliable coolant change in your MMY dirt bike.

What You'll Need

  • Fresh coolant (consult your KTM owner's manual for specs, but a high-quality engine coolant or premix like Engine Ice is commonly chosen)
  • Bucket or drain pan
  • 8mm socket or wrench
  • Funnel
  • T30 Torx bit (for some shroud bolts)
  • Torque wrench (recommended)
  • Clean rags
  • Distilled water (for flushing, if needed)

Step 1: Prepare the Bike

  • Ensure the engine is completely cool. Serious burns and damage can occur if you open the system while hot.
  • Stabilize the bike on a stand or level surface.

Step 2: Remove the Skid Plate and Shrouds (If Needed)

  • Depending on your setup, you may need to remove the skid plate or left radiator shroud for easier access to the radiator cap and water pump drain bolt. Use your T30 Torx bit as needed.

Step 3: Remove the Radiator Cap

  • Slowly remove the radiator cap to release any residual pressure and allow airflow for draining.

Step 4: Drain the Coolant

  • Locate the coolant drain bolt on the water pump cover (lower right engine area).
  • Position your bucket or drain pan under the drain bolt.
  • Using the 8mm wrench, remove the drain bolt. Allow the coolant to fully drain. Remove the left radiator lower hose if you want a more complete drain (not always required).
  • If flushing, reinstall the bolt, fill with distilled water, run for a short period, then repeat the drain to clear any old coolant.

Step 5: Reinstall the Drain Bolt

  • Clean the bolt and copper washer. Reinstall and torque the bolt to manufacturer specs (always check your manual, typically around 6 Nm for KTM models).

Step 6: Filling and Bleeding the System

  • Pour the new coolant into the left radiator using a funnel.
  • The 350XCFW features a bleed screw at the top of the cylinder head (small 8mm or 6mm bolt). Loosen this just enough to allow air to escape as you fill. Watch for coolant to seep from the screw – as soon as a steady stream comes out (no bubbles), retighten the screw.
  • Continue filling at the radiator until it is topped off.
  • Reinstall the radiator cap.

Step 7: Warm Up & Recheck

  • Start the bike and let it idle for several minutes with the radiator cap on. Tip the bike side to side to help air escape.
  • Shut off, let cool, then recheck coolant level – top off if necessary.
  • Inspect for leaks at the drain bolt and around hoses.

2023 KTM 350XCFW-Specific Tips

  • This model uses KTM's compact four-valve head with a high-performance cooling circuit. Proper bleeding through the head bleed screw is crucial to avoid hot spots and air pockets.
  • The cooling system is relatively compact; do not overfill – use the radiator top baffle as your guide.
  • KTM recommends engine ice or coolant with adequate corrosion protection and a freeze point below -25°C for full protection.
  • The 350XCFW does not have a separate coolant reservoir; all filling is done at the radiator.

Final Notes

  • Proper coolant maintenance extends engine and water pump life. Check your manual for service intervals and use only recommended coolants for aluminum engines.
  • If you experience repeated overheating after a coolant change, re-bleed the system thoroughly. Persistent bubbles may indicate a leak that requires further inspection.

Related Shopping Categories

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Shop Coolant for a 2023 KTM 350XCFW Dirt Bike.

Shop Temperature Sensors for a 2023 KTM 350XCFW Dirt Bike.

Shop Tools for a 2023 KTM 350XCFW Dirt Bike.

Shop Radiator Hoses for a 2023 KTM 350XCFW 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.