How to Change the Coolant in a 2000 Cobra BM50
Shop parts for a 2000 Cobra BM50 Dirt Bike.
Maintaining the proper coolant level in your 2000 Cobra BM50 is essential for the engine's longevity and peak performance. Fresh coolant not only prevents overheating but also safeguards critical internal components from corrosion and deposits. Here is MotoSport's proprietary, step-by-step guide for changing the coolant on this high-performance mini dirt bike.
Before You Begin
- Let the engine cool completely. Draining coolant from a hot engine can be dangerous.
- Prepare about 500ml of quality engine coolant (premixed, non-silicate, compatible with aluminum components).
- Gather tools: Phillips screwdriver, small container, funnel, fresh hose clamps (if needed), and gloves.
Step-by-Step Coolant Change Process
- Remove seat and side panels to easily access the radiator and reservoir.
- Open the radiator cap slowly to release any residual pressure. The cap is usually on the left side, atop the radiator.
- Drain the old coolant:
- Locate the radiator drain bolt (lower part of radiator or water pump housing). Position your container beneath the drain point.
- Remove the drain bolt or loosen the lowest hose clamp, allowing the coolant to flow out.
- For a thorough flush, gently tip the bike or disconnect a lower hose to assist full drainage.
- Inspect the system for debris or corrosion. Replace any worn hoses or clamps.
- Secure the drain bolt or hose and ensure all connections are tight. Use a new washer on the drain bolt if needed to prevent leaks.
- Add new coolant:
- Slowly pour coolant into the radiator using a funnel. The BM50 holds about 450–500ml.
- Fill until you see coolant at the base of the filler neck. Top up the expansion tank to its upper mark.
- "Burp" the cooling system to expel air:
- Firmly squeeze the large radiator hose, or disconnect and slightly lift a return line to let trapped air escape. Watch for bubbles in the filler neck.
- Continue slowly topping off until no more bubbles emerge.
- Start the engine and idle for several minutes. Gently rev (no hard throttle) to further purge air.
- Shut down and cool. Once fully cooled, check the coolant level in both the radiator and the reservoir. Top up if needed.
- Verify no leaks at hose joints and drain points. Reinstall seat and panels.
Important Notes for 2000 Cobra BM50 Owners
- The BM50’s compact race-tuned two-stroke engine runs at higher RPMs than most mini dirt bikes—keeping coolant fresh is vital for reliability.
- Always use non-silicate, motorcycle-appropriate coolant to protect aluminum radiators and water pumps.
- Check coolant level periodically, especially after the first few rides post-change, as any air left in the system may bleed out.
- Flush coolant yearly if you race or ride hard, or every two years for light use.
Regular coolant changes ensure your 2000 Cobra BM50 stays fast, safe, and race-ready. If you need replacement parts or want to upgrade cooling components, MotoSport stocks everything you need for this iconic youth competition bike.
Related Shopping Categories
Shop Radiators for a 2000 Cobra BM50 Dirt Bike.
Shop Coolant for a 2000 Cobra BM50 Dirt Bike.
Shop Temperature Sensors for a 2000 Cobra BM50 Dirt Bike.
Shop Tools for a 2000 Cobra BM50 Dirt Bike.
Shop Radiator Hoses for a 2000 Cobra BM50 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.
