How to Change the Coolant in a 2025 Honda CRF150R

Shop parts for a 2025 Honda CRF150R Dirt Bike.

Routine coolant changes are essential for maintaining the performance & longevity of your 2025 Honda CRF150R. This mini motocrosser's high-revving 4-stroke engine runs best with a properly maintained cooling system. Here's a comprehensive, MotoSport-exclusive guide to changing your coolant – whether your ride's hitting the track or trails.

What You Need

  • Fresh approved coolant (Honda Pro HP Coolant or equivalent)
  • Drain pan
  • 8mm socket or wrench
  • Funnel
  • Distilled water (optional, for flushing)
  • Shop rags and a small brush (for any spills/cleanup)
  • Torque wrench (recommended)

Step-by-Step Coolant Change Procedure

  1. Prepare the Motorcycle
    • Make sure the engine is completely cool before starting. Hot coolant can cause serious burns.
    • Place the bike on a level surface with a stand for stability.
    • Remove the radiator cap (on the left radiator), but only after ensuring the engine has cooled.
  2. Drain the Old Coolant
    • Locate the water pump – it's on the lower right side of the engine.
    • Identify the lowest (drain) bolt on the water pump cover; have your drain pan ready underneath.
    • Using an 8mm socket, remove the drain bolt. Coolant will begin to flow out.
    • Tip: Removing the radiator cap helps coolant drain more quickly by allowing air in the system.
  3. Optional: Flush the System
    • To fully flush out old coolant or contaminants, re-install the drain bolt gently and pour distilled water into the radiator (do not use tap water).
    • Remove the drain bolt and let the water run out. Repeat until the drained fluid runs clear.
  4. Reinstall the Drain Bolt
    • Inspect the copper washer on the drain bolt; replace if damaged or crushed. Tighten the drain bolt securely (don't overtighten).
  5. Add New Coolant
    • Slowly fill the radiator with your chosen premixed coolant, using a funnel to avoid splashes.
    • If refilling after a disassembly or complete system flush, the 2025 CRF150R holds about 0.76 liters (0.80 US qt) of coolant.
    • Fill until the coolant sits just below the base of the radiator filler neck.
  6. Bleed the Cooling System
    • Tilting the bike gently side to side helps release trapped air.
    • Reinstall the radiator cap securely.
    • Start the bike and let it idle for two to three minutes. Shut it off and let it cool.
    • Remove the radiator cap again and check the coolant level; top off if needed.

CRF150R Model Specific Tips & Notes

  • The CRF150R uses a high-revving, liquid-cooled engine. Never run straight water; always use quality premixed coolant for anti-corrosion and proper boiling protection.
  • The cooling system is pressurized. Always wait for the bike to cool before opening the radiator cap to avoid injury.
  • Inspect hoses and clamps during your coolant change. Look for signs of leaks or cracking, which are important for this performance-oriented machine.
  • Double-check after your first ride; coolant level can drop as trapped air works its way out of the system.
  • Dispose of old coolant responsibly according to local environmental regulations.

Keeping Your 2025 CRF150R Performing at Its Best

Coolant maintenance is key to protecting your CRF150R's engine – especially during hard riding or racing. Sticking to regular change intervals (at least every year or after heavy use) helps prevent overheating, corrosion, and expensive repairs. For genuine parts and fluids, MotoSport has you covered.

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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.