How to Change the Coolant in a 2023 Honda CRF150R Big Wheel

Shop parts for a 2023 Honda CRF150R Dirt Bike.

Changing the coolant in your 2023 Honda CRF150R Big Wheel is a straightforward maintenance task that protects your engine from overheating and ensures optimal performance. The following proprietary MotoSport guide gives you step-by-step instructions and tips tailored to this high-performance competition dirt bike.

Why Change Your Coolant?

The CRF150R RB is designed for competition, running hot during hard laps or trail riding. Old or contaminated coolant loses both its cooling efficiency and anti-corrosion properties. Regular coolant replacement (at least once every season or after racing) prevents overheating, scale buildup, and premature wear of water pump seals and gaskets.

Tools & Materials Needed

  • Fresh coolant (Honda Pro HP Coolant or compatible premixed motorcycle coolant)
  • 8mm or 10mm socket or wrench
  • Drain pan
  • Funnel
  • Distilled water (if you flush the system)
  • Clean rags or shop towels
  • Protective gloves

1. Prepare the Bike

  • Make sure the engine is completely cool before starting.
  • Stand your CRF150R RB upright and secure it on a stand or level surface.
  • Remove the radiator cap slowly – never when the engine is hot, as pressurized coolant can spray out and cause burns.

2. Drain the Old Coolant

  • Locate the coolant drain bolt on the lower right side of the engine (water pump cover). Place your drain pan, then unscrew the drain bolt and its sealing washer using your socket or wrench.
  • If present, loosen the radiator cap to help drainage. Let the coolant completely empty into the pan.
  • Optional: Remove the radiator lower hose for faster draining.
  • If flushing, pour distilled water into the radiator, reinstall the bolt, run briefly, and drain again. Repeat until the flush runs clear.

3. Install the Drain Bolt

  • Inspect the drain bolt sealing washer for cracks or wear. Replace if necessary for a leak-free seal.
  • Reinstall the drain bolt and snug it to factory torque (typically 9 Nm/80 in-lb). Don't overtighten – you can crack the cover.

4. Refill the Cooling System

  • Using a clean funnel, pour the new coolant into the radiator neck slowly until it's just below the rim.
  • It's crucial to use motorcycle-specific coolant and avoid tap water, which causes mineral deposits and system damage.

5. Remove Air Pockets

  • With the cap off, briefly tip the bike side to side to help trapped air escape. You can also gently squeeze the hoses.
  • Start the engine and let it idle for a minute. Watch for air bubbles escaping. Add coolant if the level drops.
  • Repeat until the coolant stays at the neck after running, with no bubbles.
  • Install the radiator cap securely.

6. Final Checks

  • Wipe any spilled coolant – it's slippery on plastic or metal and toxic to pets.
  • Check for leaks around the drain bolt, hoses, and radiator cap.
  • After your next ride, recheck the coolant level when cool and top off if needed.

Special Notes for the CRF150R RB

  • The 2023 CRF150R RB has a compact, high-revving engine that runs hotter than trail bikes. Don't skip regular coolant changes.
  • The system holds about 0.76 liters (0.80 US quarts).
  • Never use tap water, as it can cause corrosion and damage the magnesium water pump cover.
  • This model is competition-focused, with lightweight, high-flow radiators – so cooling is mission-critical, especially for young racers.
  • Check hoses and the radiator cap seal for wear or swelling, as age or improper coolant can degrade these quickly.

Stay Race Ready with Regular Maintenance

A healthy cooling system means maximum reliability from your CRF150R RB. Always inspect and replace coolant at recommended intervals or after any sign of overheating. For direct-fit parts, coolant hoses, upgraded radiators, and more, trust MotoSport for parts that keep your ride dialed in for every gate drop.

Related Shopping Categories

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Shop Tools for a 2023 Honda CRF150R Dirt Bike.

Shop Radiator Hoses for a 2023 Honda CRF150R 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.