How to Change the Coolant in a 2018 Yamaha WR250R (Dual Sport)

Shop parts for a 2018 Yamaha WR250R Dirt Bike.

Changing the coolant in your 2018 Yamaha WR250R is a crucial part of routine maintenance, ensuring your engine runs at optimal temperatures and avoids overheating. The WR250R–Yamaha's renowned dual-sport–features a compact liquid-cooled engine where coolant quality and level directly impact long-term performance. Here‘s a proprietary MotoSport guide for a proper, thorough coolant change designed specifically for your model.

What You‘ll Need

  • Coolant (recommend Yamaha Yamalube or a premium motorcycle-safe coolant)
  • Distilled water (for flushing, if needed)
  • Funnel
  • Drain pan
  • Allen keys
  • 8mm socket and ratchet
  • Phillips head screwdriver
  • New copper washer (for drain bolt)
  • Shop rags
  • Protective gloves/safety glasses

Step-by-Step Coolant Change Guide

  1. Prepare Your Bike & Work Area:
    • Ensure the engine is completely cool. Never attempt to open the radiator cap when the engine is hot–serious injuries can result from pressurized, scalding coolant escaping.
    • Place your WR250R on a stable stand or level surface.
  2. Remove Panels & Seat:
    • Loosen and remove the seat and both left and right air scoops using Allen keys and the 8mm socket. This provides access to the radiator and reservoir tank.
  3. Remove the Coolant Reservoir
    • Locate the coolant recovery tank. Disconnect the vent hose and the dip tube.
    • Unscrew the reservoir mounting bolts. Carefully extract the tank (removal can be tight; moving the vent tube helps).
    • Drain the reservoir into the drain pan and set it aside for cleaning if necessary.
  4. Drain the Radiator & Engine:
    • Ensure a rag is over the radiator cap; slowly loosen the cap counterclockwise to release any internal pressure. Once the hissing stops, remove the cap fully.
    • Locate the coolant drain bolt at the water pump (typically at the lower right side of the engine). Place your drain pan underneath, then remove the drain bolt along with its copper washer.
    • Allow all coolant to drain from both the engine and the radiator.
  5. Flush (Optional but Recommended):
    • If the drained coolant was particularly dirty, flush the system with distilled water. Reinstall the drain bolt, fill with distilled water, run the engine briefly, then repeat the drain procedure.
  6. Reassemble with New Parts:
    • Install a new copper washer on the drain bolt. Tighten the bolt to 10 Nm (7.2 ft–lb).
    • Reinstall the reservoir tank and reattach hoses.
  7. Refill the Cooling System:
    • Use a funnel to fill the radiator with your chosen coolant until it reaches the filler neck.
    • Add coolant to the reservoir tank up to the “full” line.
    • Do not overfill.
  8. Bleed Air from the System:
    • Leave the radiator cap off, start the engine, and let it idle for a few minutes. Watch for air bubbles as trapped air purges from the system.
    • Add coolant as the level drops; stop when the system stabilizes.
    • Reinstall the radiator cap securely.
  9. Check for Leaks:
    • Inspect all hoses, drain bolt, and reservoir connections for any seepage.
  10. Reassemble Panels & Clean Up:
    • Reinstall the seat and side panels. Clean up any spilled fluid and responsibly dispose of spent coolant.

WR250R Owner‘s Notes & Tips

  • The WR250R cooling system capacity is modest; use care not to overfill. Always verify levels after a test ride and top up if needed.
  • Mixing incompatible coolants (for example, silicate-based with ethylene glycol) can cause gel formation–stick with Yamaha Yamalube or a proven alternative labeled for aluminum engines.
  • Harsh off-road riding or frequent mud exposure will clog radiator fins faster. Gently hose off debris after rides but avoid high-pressure water directly at radiator seals.
  • This model‘s reservoir tank is more difficult to remove than many dual sports, so handle securing tabs and hoses with care to avoid breakage.

By following this MotoSport-exclusive guide, you can keep your Yamaha WR250R running reliably, whether on the trail or the tarmac.

Related Shopping Categories

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Shop Radiator Hoses for a 2018 Yamaha WR250R 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.