How to Change the Coolant in a 2020 Honda CRF250RX: Step-by-Step Guide

Shop parts for a 2020 Honda CRF250RX Dirt Bike.

Maintaining your 2020 Honda CRF250RX in top condition means regular coolant changes to prevent overheating and ensure optimal performance. This model's advanced liquid cooling system is built for serious off-road ridingkeeping your engine running cooler, longer. Changing the coolant yourself is straightforward, but following the correct process is essential for both function and safety. Here is your proprietary MotoSport guide:

What You’ll Need

  • Fresh, silicate-free motorcycle coolant
  • Drain pan
  • Ratcheting wrench set (8mm, 10mm sockets)
  • Phillips head screwdriver
  • Funnel
  • Clean water for flushing
  • Shop towels or rags
  • OEM radiator cap and new crush washer (recommended)
  • Protective gloves

Step 1: Remove the Seat & Side Covers

  • Remove the seat by unbolting it and set it aside.
  • Use your wrench to remove the two radiator shroud bolts and side cover bolts. Slide the shroud upward to release it, then remove the side cover by releasing the tab from the seat support base. Installation is reversed after service–torque specs: 10 N·m for shroud and side cover bolts.

Step 2: Remove the Radiator Cap

  • Always make sure the bike is completely cool before proceeding—hot coolant is dangerous.
  • Use a Phillips screwdriver to remove the set screw on the radiator cap, then carefully remove the cap itself.

Step 3: Drain the Coolant

  • Position your drain pan underneath the water pump cover (lower right side of the engine).
  • Remove the coolant drain bolt. Allow coolant to fully drain from both the radiator and reserve tank.

Step 4: Flush the System (Optional)

  • Pour clean water through the radiator fill neck to rinse out old coolant. If changing coolant types, flush with a 50/50 vinegar-water mix, then rinse again with clean water.

Step 5: Reinstall the Drain Bolt

  • Install a new crush washer (if available) and reinstall the drain bolt. Tighten securely but do not over-torque.

Step 6: Add New Coolant

  • Using a funnel, pour coolant into the radiator fill opening. Do not reinstall the cap yet.
  • Tip the motorcycle about 20° left and right several times. This step helps bleed air out of the system. Add coolant as the level drops, repeating until it remains steady.

Step 7: Bleed Remaining Air

  • Start the engine and let it idle for 2–3 minutes. Snap the throttle several times while monitoring the coolant level in the reserve tank, not the radiator (never open the radiator once hot).
  • If needed, add coolant to the reserve tank to bring it to the "MIN" mark, never above "MAX."

Step 8: Secure Everything & Check for Leaks

  • Reinstall the radiator cap and secure the set screw.
  • Reattach the body panels, shroud, and seat using factory alignment tabs. Torque fasteners to spec.
  • Start the bike, let it reach operating temperature, and inspect for leaks at the drain bolt and hoses. Double-check coolant level in the overflow once the engine has cooled.

CRF250RX Model Notes

  • The CRF250RX uses a high-capacity dual-radiator system designed for grueling off-road conditions. Trapped air will quickly cause overheating—so careful bleeding is critical for this chassis.
  • Honda recommends checking the radiator and reserve tank connections after every coolant change. A properly filled & bled system is the best way to avoid trail shutdowns.
  • Only use silicate-free, motorcycle-specific coolant. Never use tap water or automotive coolant in this system.

Keep your CRF250RX running cool and reliable wherever you ride. For all your replacement parts or Honda-approved coolant needs, remember:

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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.