How to Change the Coolant in a 2015 KTM 350SXF
Shop parts for a 2015 KTM 350SXF Dirt Bike.
Routine coolant changes on your 2015 KTM 350SXF are key to maintaining optimal engine temperature and longevity, especially given the high-performance demands of this motocross machine. Follow this MotoSport-exclusive guide to ensure your coolant swap is done right – with tips tailored to your KTM's unique setup.
What You Will Need
- Fresh coolant suitable for aluminum engines (silicate-free recommended by KTM)
- 8mm socket (for the water pump drain bolt)
- Catch pan
- Funnel
- Distilled water (optional, for flushing)
- Gloves and rags for cleanup
Step-by-Step Coolant Change Guide
- Allow Your Bike to Cool. Never attempt to remove the radiator cap while the engine is hot—scalding coolant may spray under pressure.
- Remove the Seat and Shrouds (if needed). On the 2015 350SXF, you may need to remove the seat and left side radiator shroud for easier access to the radiator fill cap.
- Access the Radiator Cap. Unscrew and remove the radiator cap to release system pressure and allow air in as the coolant drains.
- Locate the Drain Bolt. The coolant drain is a small bolt on the water pump cover on the right side of the engine—this is an 8mm bolt. Place your catch pan under the area.
- Remove the Drain Bolt. Loosen the bolt and let the coolant fully drain from the engine and radiators. For a more thorough drain, you can also gently tilt the bike side to side.
- Optional: Flush the System. For best maintenance, briefly reinstall the drain bolt, refill with distilled water, run the engine for a minute, allow to cool, then drain again. This helps remove old coolant and contaminants.
- Replace and Tighten the Drain Bolt. Ensure the sealing washer is in good shape and torque the bolt to specification, taking care not to overtighten (typically just snug for this size bolt).
- Add Fresh Coolant. With the bike upright, slowly pour the new coolant into the radiator using a funnel. Fill until the fluid reaches just below the radiator neck.
- Bleed the Cooling System. Gently rock the bike or squeeze the radiator hoses to help remove trapped air bubbles. After the first fill, briefly start the engine (with cap off), let it idle, then top off as the level drops. Be cautious—do not overfill.
- Re-install the Radiator Cap. Once the system is filled and bled, securely reinstall the cap.
- Inspect for Leaks. Start your engine, allow it to reach operating temperature, then shut it off and check for leaks around the drain bolt and hoses. Recheck coolant level after first ride and top off as needed.
2015 KTM 350SXF–Specific Tips
- The 350SXF does not have a separate coolant overflow reservoir found on some other models, making proper bleeding and refilling critical.
- This engine is prone to running hot, so consider a high-performance coolant if riding aggressively or in hot environments. Always use coolant rated for high-revving, aluminum block motocross bikes.
- Inspect radiator fins and hoses for damage or obstructions—this model's radiators are exposed and vulnerable to roost and tip-over damage.
- The KTM's water pump O-rings and gaskets can degrade; inspect for crusty residue around the pump and replace if needed during your coolant change.
Coolant Change Frequency
- KTM recommends a coolant change at least every year or 15-20 hours for competitive use.
- Any signs of overheating, coolant loss, or contaminated fluids mean you should change it sooner.
Keeping your 2015 KTM 350SXF's cooling system maintained prevents costly repairs and keeps your machine running at peak power lap after lap. For everything you need, from radiators to fresh coolant and gasket kits, MotoSport has you covered.
Related Shopping Categories
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Shop Radiator Hoses for a 2015 KTM 350SXF 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.