How to Change the Coolant in a 2023 KTM 350XCF

Shop parts for a 2023 KTM 350XCF Dirt Bike.

Routine coolant changes keep your 2023 KTM 350XCF running cool – both on the trail and at the track. The 350XCF uses a high-performance, liquid-cooled engine, making a properly maintained cooling system critical for peak performance and longevity. Below, you'll find a MotoSport exclusive, step-by-step guide to flushing and replacing your coolant, along with key tips unique to this model.

What You'll Need

  • Fresh, silicate-free motorcycle coolant (never use automotive coolant)
  • 8 mm wrench or socket (for water pump drain bolt)
  • Drain pan or container
  • Funnel
  • Shop towels
  • Torque wrench (recommended for reinstallation)
  • Protective gloves

Step 1 – Preparation

  • Make sure your bike is completely cool—never open the cooling system when hot to avoid burns.
  • Position the bike upright on a level surface.
  • Remove the seat and necessary side panels for radiator access.

Step 2 – Remove the Radiator Cap

  • Find the radiator cap on the right side. Turn counterclockwise and lift it off.
  • This relieves any residual pressure and allows coolant to drain freely.

Step 3 – Drain the Old Coolant

  • Place your drain pan under the water pump on the right side of the engine.
  • Use your 8 mm wrench to remove the lower water pump screwthis is the dedicated drain bolt for the cooling system.
  • Allow all coolant to drain completely. Tilting the bike slightly can help expel more fluid.
  • Inspect the removed bolt and replace its seal washer if damaged or crusty.

Step 4 – Reinstall the Drain Bolt

  • Once drained, reinstall the drain bolt and torque it to the manufacturer's spec (10 Nm for most KTM 350 models) using a torque wrench.

Step 5 – Refill with Fresh Coolant and Bleed Air

  • Slowly pour new coolant into the radiator neck using a funnel, until coolant is visible at the top.
  • On the 350XCF, a small air bleeder screw is located at the top of the cylinder head or on the thermostat housing (consult your owner's manual for location). Crack this screw as you fill—when coolant seeps out steadily, tighten the screw to expel trapped air.
  • Top off the radiator if the level dropped after bleeding.

Step 6 – Final Checks

  • Reinstall the radiator cap securely.
  • Wipe up spills and check for leaks at the drain bolt and any hoses disturbed.
  • Start the engine and let it idle for a few minutes. Watch the coolant level and temperature—shut off the engine if anything seems off.
  • Let the bike cool down, then recheck the coolant level and top off if necessary. Install seat and side panel.

2023 KTM 350XCF-Specific Tips

  • The 350XCF uses a compact radiator design. Do not overfill the system—leave space for heat expansion (coolant should just touch the bottom of the radiator neck).
  • OEM coolant is orange. If switching to another color, flush the system fully with distilled water to avoid mixing chemical types.
  • Avoid using "water wetter" or non-motorcycle coolants; this can harm magnesium engine and pump components.
  • Check radiator hoses for cuts or swelling during your service—replace if needed to prevent failure under pressure.

When to Change Coolant

  • KTM recommends every two years, but for hard racers or hostile climates, yearly is better for maximum protection.
  • Always replace coolant after any significant engine or cooling system work.

Keep your 2023 KTM 350XCF running at peak performance with regular coolant changes—and enjoy the confidence of a bike that stays cool under pressure.

Related Shopping Categories

Shop Radiators for a 2023 KTM 350XCF Dirt Bike.

Shop Coolant for a 2023 KTM 350XCF Dirt Bike.

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

Shop Tools for a 2023 KTM 350XCF Dirt Bike.

Shop Radiator Hoses for a 2023 KTM 350XCF 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.