How to Change the Coolant in a 2018 Kawasaki KLX250: MotoSport Guide
Keeping your 2018 Kawasaki KLX250's cooling system fresh is key to maintaining peak performance on all your rides. Whether it&rsquos routine maintenance or part of a bigger rebuild, changing the coolant ensures that your dirt bike stays cool under pressure and is protected from engine-damaging corrosion.
Tools & Supplies Needed
- Socket wrench set (8mm and 10mm recommended)
- Drain pan
- Pliers (for hose clamps, if needed)
- Funnel
- Distilled water (for flushing)
- Manufacturer-appropriate coolant (avoid pre-mixed automotive coolants not rated for motorcycles)
- Clean shop rags
- Safety gloves
Before You Begin
- Ensure the engine is completely cool before starting. Never open the radiator cap on a hot engine – pressure and hot coolant can cause injury.
- Work in a well-ventilated area and keep coolant away from pets & children (it's toxic).
Instructions: Step-by-Step Coolant Change for the KLX250
- Remove the Side Panel: Use your 8mm or 10mm socket to remove the side panel and access the coolant overflow reservoir tank.
-
Drain the Old Coolant:
- Place your drain pan underneath the bike, below the water pump/coolant drain bolt (located at the lowest point on the right side of the engine).
- Remove the radiator cap first to equalize the pressure.
- Use a socket to carefully unscrew the coolant drain bolt and let the coolant pour into your pan. Gently tilt the bike to get as much fluid out as possible.
- Remove the reservoir tank cap and pour out any remaining coolant from the overflow tank.
-
Flush the System (Recommended):
- Temporarily reinstall the drain bolt.
- Fill the cooling system with distilled water via the radiator filler neck, and replace the cap.
- Start the bike and let it idle for a minute or two (watch temperature). Shut down. Repeat step 2 to drain the flush water.
- Repeat for a second flush if the water comes out dirty.
-
Refill With Fresh Coolant:
- Reinstall the drain bolt and tighten securely (don't overtighten).
- Use a funnel to slowly pour approved coolant into the radiator until it reaches the top. Fill the overflow reservoir to the "Full" line.
- Pause and rock the bike side-to-side & squeeze hoses gently. This helps push out air pockets.
-
Bleed Air and Top Off:
- Keep the radiator cap off. Start the engine and allow it to idle for a minute – you may see bubbles escape as trapped air works out.
- Shut off the bike, top off coolant as needed, and reinstall the radiator cap securely.
- Wipe up any spills and reinstall the side panel.
-
Final Checks:
- After one or two short rides, recheck the coolant level. Fill the overflow tank if needed.
- Inspect for leaks at the drain bolt, radiator cap, and hoses.
KLX250-Specific Tips & Notes
- The KLX250 has a fairly low coolant capacity, so be sure not to overfill – excess can lead to leaks or overflow.
- Use only motorcycle-safe, silicate-free coolant designed for aluminum engines. This prevents water pump damage and internal corrosion.
- Pay attention to the hose clamps and radiator condition: dirt riding can loosen hardware or deform radiators from tip-overs. Tighten clamps if any seepage appears.
- The 2018 KLX250's fuel-injected engine runs hotter than older carb models, making fresh coolant and a clean system even more important for reliable performance in varied riding conditions.
Related Shopping Categories
Shop Radiators for a 2018 Kawasaki KLX250 Dirt Bike.
Shop Coolant for a 2018 Kawasaki KLX250 Dirt Bike.
Shop Temperature Sensors for a 2018 Kawasaki KLX250 Dirt Bike.
Shop Tools for a 2018 Kawasaki KLX250 Dirt Bike.
Shop Radiator Hoses for a 2018 Kawasaki KLX250 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.