How to Change the Coolant in a 2006 Honda CR125
Shop parts for a 2006 Honda CR125 Dirt Bike.
Regular coolant changes are essential for maintaining optimal performance and longevity of your 2006 Honda CR125. This two-stroke motocross machine relies on fresh coolant for efficient heat dissipation and to avoid overheating – especially during demanding rides or race conditions. Below is a unique guide, tailored to MotoSport.com customers, for safely and effectively changing the coolant in your CR125, along with model-specific tips every owner should know.
Essential Supplies
- Chemical-resistant gloves & safety glasses
- Drain pan
- New coolant (glycol-based, or as specified by Honda)
- Distilled water (if diluting concentrated coolant)
- Socket or wrench set
- Copper washer (replacement for drain bolt, if needed)
- Rag for spills
Step-by-Step Coolant Replacement Process
- Ensure the bike is completely cool. Never open the cooling system when hot – risk of burns and injury.
- Position the CR125 upright. Use a stand for stability, and remove the seat and left radiator shroud for easier access.
- Place the drain pan beneath the water pump. The drain bolt is typically located at the bottom of the water pump cover.
- Remove the radiator cap. This step will help coolant flow out quickly due to air entering the system.
- Remove the water pump drain bolt. Allow coolant to completely drain. Inspect the old coolant—milky or contaminated coolant may indicate internal issues that need further attention.
Tip: Replacing the copper washer on the drain bolt each time can prevent leaks. - Reinstall & torque the drain bolt. Tighten to 10 Nm to avoid damaging threads or causing leaks.
- Fill the radiator with new coolant. Use premixed glycol-based coolant, or mix with distilled water as recommended.
- Bleed air from the system. Gently tilt or bounce the bike to release trapped air bubbles. Once filled, briefly run the engine with the radiator cap off and top up as needed. Ensure no air pockets remain.
- Reinstall the radiator cap securely. Make sure it clicks fully into place for a proper seal.
- Reinstall all removed plastics. Wipe away any spills and dispose of old coolant responsibly.
Model-Specific Notes for the 2006 CR125
- This CR125 relies on a two-radiator system—always fill slowly and compare both radiators to prevent uneven levels.
- Check for damage to radiator fins or hoses—off-road impacts can cause leaks or compromised flow. Replace as needed to avoid overheating.
- Inspect water pump seals and gaskets periodically. A leaking water pump or presence of coolant in the oil (milky appearance) suggests a seal failure, and immediate service is recommended.
- Honda recommends seasonal coolant flushes, and more frequently if riding in muddy, sandy, or extreme heat conditions.
Performance & Maintenance Tips
- Never mix different coolant types or brands—always fully flush the system if switching coolants.
- After your first ride with fresh coolant, let the bike cool and recheck the coolant level—top up if necessary to account for trapped air being released.
- Use only distilled water for dilution to prevent mineral deposits that reduce cooling efficiency.
Stay on top of regular coolant replacements to keep your 2006 Honda CR125 performing at its peak, whether at the track or on the trail.
Related Shopping Categories
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Shop Radiator Hoses for a 2006 Honda CR125 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.