How to Change the Coolant in a 2017 KTM 250EXCF

Shop parts for a 2017 KTM 250EXCF Dirt Bike.

Routine coolant changes are key to keeping your 2017 KTM 250EXCF running cool and performing at its best, especially under demanding riding conditions. Follow this specialized MotoSport guide for a step-by-step approach tailored to your EXCF's unique setup, including tips you won't find in generic manuals.

Preparation – What You'll Need

  • Fresh premixed motorcycle coolant rated for aluminum engines
  • Distilled water (for flushing – optional but recommended when switching coolant types)
  • 10mm wrench or socket
  • Drain pan
  • Funnel
  • Clean rags for spills
  • Torque wrench (for reassembly, optional)
  • Protective gloves

Step 1: Let the Engine Cool

The cooling system is pressurized when hot. Always let your KTM 250EXCF cool down completely before servicing. This prevents serious burns and ensures accurate coolant level readings.

Step 2: Remove the Skid Plate (If Installed)

Some bikes have an aftermarket or OEM skid plate blocking access to the water pump. Remove it with the appropriate tools as needed.

Step 3: Remove the Radiator Cap

With the bike upright and on level ground, slowly twist off the radiator cap to release any residual pressure. This allows proper drainage and avoids airlocks during refilling.

Step 4: Drain the Old Coolant

  • Locate the coolant drain bolt – on the 2017 KTM 250EXCF, it's at the bottom of the water pump cover on the right side of the engine.
  • Place your drain pan under the bolt.
  • Use a 10mm wrench to loosen and remove the bolt. Allow coolant to fully drain.
  • Check the old coolant for excessive debris, oil, or rust. Contaminated fluid may indicate other engine issues that need attention.

Step 5: Optional – Flush the System

If switching coolant types or after years of service, add distilled water through the radiator neck, reinstall the drain bolt, run the bike briefly (2-3 minutes), then repeat the drain process to thoroughly flush the system. Do not use tap water, as minerals can damage cooling passages.

Step 6: Reinstall the Drain Bolt

  • Inspect the sealing washer for damage – replace if crushed or split.
  • Hand-tighten the drain bolt, then torque to factory spec if possible (typically about 6-9 Nm).

Step 7: Fill with New Coolant

  • Slowly pour new coolant into the radiator until the fluid reaches the top of the filler neck.
  • Pause mid-fill to squeeze the lower radiator hose. This helps release trapped air bubbles.
  • On EXCF models, slightly rocking the bike or raising the front wheel by about 19 inches can further help air escape from the cylinder head and cooling system cavities.

Step 8: Bleed the System

  • Some KTM EXCF models have bleed screws on the cylinder head. Open these until coolant flows steady, then tighten.
  • If no specific bleed screw, cycle the cooling system by running the bike for a minute with the cap off, topping off the coolant as bubbles surface.

Step 9: Reinstall the Radiator Cap and Run the Engine

  • Seal the radiator and start the engine – let it idle until fully warm.
  • Shut down, let cool, and recheck coolant level – top off if necessary. Check for any leaks around the drain bolt and hoses.

Step 10: Dispose of Old Coolant Properly

Used coolant is toxic and must not be poured down drains or on the ground. Most auto parts stores or waste facilities accept used coolant for recycling.

2017 KTM 250EXCF Owner Tips & Model-Specific Notes

  • Factory interval for coolant change is every 40-50 hours of operation. Hard-riding in extreme heat or racing conditions may warrant more frequent changes.
  • The 250EXCF's robust dual-radiator design is highly efficient but can trap air easily – take extra time to bleed thoroughly for optimal performance.
  • Consider using a high-performance coolant to provide extra protection against boil-over in technical singletrack or slow-speed riding.
  • Always inspect radiator hoses and clamps during coolant changes. KTM hoses can become brittle over time and are easy to replace preventively.

Your 250EXCF will thank you with cooler, more consistent performance on every ride. Keeping up with regular coolant maintenance is one of the simplest ways to extend the life of your KTM's legendary four-stroke engine.

Related Shopping Categories

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Shop Radiator Hoses for a 2017 KTM 250EXCF 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.