How to Change the Coolant in a 2018 KTM 250SXF

Shop parts for a 2018 KTM 250SXF Dirt Bike.

Keeping your 2018 KTM 250SXF running cool on the track or the trail requires fresh coolant in your bike's radiators. Here's a step-by-step guide on how to change the coolant – this process is straightforward and can be done with basic tools and attention to detail. Be sure your engine is completely cool before starting to prevent burns or injury.

Tools and Supplies Needed

  • 8 mm socket or wrench
  • Catcher pan for old coolant
  • New coolant suitable for high-performance KTM engines
  • Funnel
  • Distilled water (optional for additional flush)
  • Shop rags
  • Torque wrench (recommended for final tightening)

Step 1: Remove the Radiator Cap

Begin by carefully removing the radiator cap with the engine cold. The radiator cap is located on the left side of the bike, accessible just behind the front number plate. Removing the cap will allow air to enter & help coolant drain efficiently.

Step 2: Locate & Remove the Water Pump Drain Bolt

On the KTM 250SXF, draining the coolant is accomplished by removing the water pump cover bolt located on the right side of the engine. Position your catch pan beneath the bolt, then use your 8 mm wrench to loosen and remove it. The coolant will flow out – let it fully drain.

Step 3: Flush the System (Recommended)

If the drained coolant appears dirty or contaminated, you can flush the cooling system by pouring distilled water into the radiator, reinstalling the drain bolt, starting the engine briefly, and then draining again. Repeat until the water runs clear. Always use distilled water to avoid mineral build-up.

Step 4: Reinstall the Drain Bolt

Once drainage is complete, reinstall the drain bolt. Tighten it securely – using a torque wrench set to the specifications in your owner's manual is best practice.

Step 5: Fill with New Coolant

Using a funnel, slowly add your fresh coolant into the radiator until it's about 10 mm above the radiator fins. Filling slowly helps avoid air pockets. Replace the radiator cap securely.

Step 6: Bleed the Cooling System

  • Start the engine and let it idle for a few minutes. Rev it slightly a few times to help circulate coolant and purge air from the system.
  • Turn off the engine, let it cool, then check the coolant level again. Add more if necessary so it's just above the radiator fins.

Step 7: Check Your Work

After your first ride, let the bike cool and re-check the coolant level. Top off if needed. Inspect the drain bolt and radiator cap area for leaks.

Special Notes for 2018 KTM 250SXF Owners

  • KTM's 250SXF models use a high-performance, lightweight cooling system with robust flow for race conditions. Only use premium coolant formulated for dirt bikes to protect the aluminum parts and water pump seals.
  • Inspect the radiator fins and hoses for any damage, as the 250SXF's compact frame can leave these parts more exposed in racing conditions.
  • Never mix coolant types (such as silicate-based with organic acid technology) – always fully flush if you are changing types.
  • The 2018 model's unique T-pipe and radiator hose system should be checked for leaks and tight clamping when performing cooling system maintenance. Replacement T-pipes and hoses are available if needed.

Your 2018 KTM 250SXF is built for performance, so keeping its cooling system in top condition is a must. Regular coolant changes protect your engine from overheating, corrosion, and internal wear – ensuring reliability for every ride.

Related Shopping Categories

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Shop Coolant for a 2018 KTM 250SXF Dirt Bike.

Shop Temperature Sensors for a 2018 KTM 250SXF Dirt Bike.

Shop Tools for a 2018 KTM 250SXF Dirt Bike.

Shop Radiator Hoses for a 2018 KTM 250SXF 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.