How to Change the Coolant in a 2011 GAS GAS EC125
Regular coolant changes are critical to keeping your 2011 GAS GAS EC125 running cool, preventing overheating, and maintaining maximum performance both on trails and track. This guide outlines a step-by-step process specifically for the EC125, plus tips unique to this model that every owner should know before servicing the cooling system.
Tools – Supplies Needed
- Fresh coolant (manufacturer-recommended, premixed or mixed to specification)
- Ratchet with suitable sockets
- Drain pan
- Funnel
- Clean shop rags
- Gloves – safety glasses
Preparation
- Ensure the bike is completely cool to the touch.
- Position the EC125 on a level surface or bike stand for safety.
- Remove plastics or fuel tank if they block the radiator cap and drain plug.
Draining the Old Coolant
- Locate the radiator cap on the left side of the bike. Slowly open it to release any residual pressure.
- Find the coolant drain bolt at the water pump cover (right side engine case, lowest bolt on the cover for most EC125s).
- Position your drain pan and remove the bolt completely. Allow all old coolant to drain. Tilt your bike slightly side-to-side if needed to fully empty the system.
- Inspect the condition of the old coolant for signs of oil or rust, which may indicate potential engine issues.
Flushing (Recommended)
- For optimal cooling, flush the system with distilled water. Reinstall the drain bolt, fill radiators with distilled water, run the engine briefly, and redrain. Repeat until only clear water drains out.
Adding New Coolant
- Reinstall the drain bolt and torque to manufacturer spec, ensuring the washer or O-ring is in good condition to prevent leaks.
- Use a funnel to fill the radiator slowly with fresh coolant up to the base of the filler neck. Tap the radiator hoses to help dislodge air bubbles during this process.
- The EC125 features a bleeder screw located on top of the cylinder head. Loosen this screw slightly to allow trapped air to escape as you fill the system, then tighten once only coolant (no bubbles) begins to escape.
Bleeding Air from Cooling System
- After topping off coolant and bleeding air, reinstall the radiator cap securely.
- Start the engine and allow it to reach full operating temperature. As it heats up, squeeze the radiator hoses to help purge any remaining trapped air.
- Once the engine is fully warm (radiators hot, fan operating if equipped), shut the bike off and let it cool fully down to ambient temperature.
- Recheck the coolant level in the radiator and overflow reservoir, and top off if necessary. This step may need repeating after the first ride as the system purges any remaining small air pockets.
What Makes the 2011 GAS GAS EC125 Unique?
- The EC125 uses a high-revving two-stroke engine, producing significant heat for its displacement. Coolant condition is especially critical to prevent overheating and detonation, especially under race conditions or extended hard riding.
- This model is known for requiring close monitoring of coolant levels after a change due to its compact radiator volume, so always check both the radiator and overflow tank after each ride, especially following coolant service.
- Always use the correct type of coolant as specified in your owner manual. Mixing coolants or using automotive types can cause gasket deterioration or reduced aluminum corrosion protection. Premixed, high-quality motorcycle coolant is recommended for the EC125.
After Service Check
- Check closely for leaks at the drain bolt, radiator hose clamps, and around the cylinder head (bleeder screw) after the first start up and after each of your next few rides.
- Monitor engine temperatures closely on your next ride, and recheck coolant levels while the bike is cool.
Pro Tip: Keeping a log of when you change your coolant can prevent overlooked maintenance and maximize the performance and life of your EC125 engine.
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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.