How to Change the Coolant in a 2010 Cobra CX50 Big Wheel: A MotoSport Guide
Shop parts for a 2010 Cobra CX50 Big Wheel Dirt Bike.
Keeping your 2010 Cobra CX50 Big Wheel performing at its best relies on proper maintenance–and that means routinely changing the coolant. The CX50 Big Wheel is a liquid-cooled 49.8cc two-stroke, designed for high-performance youth racing. It requires a specific coolant mixture and attentive care due to its compact, high-revving engine and unique cooling system design.
What You'll Need
- Fresh 50/50 mix of antifreeze-coolant and distilled water (ethylene glycol-based coolant without silicates, phosphates, or nitrates, safe for aluminum engines)
- Drain pan
- Phillips screwdriver and appropriate metric socket or wrench
- Clean shop rags
- Plastic funnel
- Safety gloves and eye protection
Step-by-Step Coolant Change on the CX50 Big Wheel
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Let the bike cool completely.
Never open the radiator cap when the engine is hot. Serious burns can result. -
Remove the seat and radiator shrouds.
Use basic hand tools to allow easy access to the radiator fill cap and overflow bottle. -
Locate and remove the radiator cap.
Use a rag to protect against any residual pressure. Set the cap aside in a clean location. -
Find the coolant drain bolt or lowest hose clamp.
On the CX50, the lowest point is typically the water pump cover. Place your drain pan underneath. Loosen the drain bolt or the lowest hose clamp on the water pump housing to allow coolant to drain completely. -
Flush the system (optional but recommended).
Pour a small amount of distilled water through the radiator to rinse out any old coolant. Loosely reinstall the drain bolt or hose and allow it to drain again, then tighten securely. -
Refill the system.
Slowly pour your 50/50 coolant/distilled water mix into the radiator. Fill up to just below the radiator neck. Tap hoses gently to help release any trapped air. -
Bleed out air bubbles.
Tilt the bike gently side to side, or squeeze and release coolant hoses to help trapped air escape. Continue filling if the level drops. - Reinstall the radiator cap securely and replace the shrouds and seat.
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Start the engine and let it idle.
Watch the coolant level in the overflow; air bubbles may continue to escape. Shut the engine off and recheck the coolant level after a minute. Top off if necessary. -
Dispose of old coolant properly.
Coolant is toxic–recycle it at a local hazardous waste center.
Important CX50 Big Wheel Owner Notes
- Coolant mix is critical: Always use a 50/50 antifreeze-coolant and distilled water ratio. Do not use tap water–minerals can damage the water pump and engine internals.
- Check for leaks after each service. The CX50's compact design means even small leaks can quickly lead to overheating.
- Monitor your radiator cap and hoses. Cracked rubber or weakness at the hose connections is a common result of repeated heat cycles. Replace as needed.
- Track performance: The CX50 is designed to run at high RPM. Overheating can cause rapid engine wear or even seizure, so a clean cooling system is essential for performance and longevity.
Proper coolant maintenance is one of the most important services you can perform on your 2010 Cobra CX50 Big Wheel. Following this guide will help ensure your bike stays fast, reliable, and race-ready all season long.
Related Shopping Categories
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Shop Tools for a 2010 Cobra CX50 Big Wheel Dirt Bike.
Shop Radiator Hoses for a 2010 Cobra CX50 Big Wheel 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.