How to Change the Coolant in a 2005 GAS GAS EC125
Regular coolant replacement is crucial for maintaining peak performance & engine longevity in your 2005 GAS GAS EC125. The EC125's high-revving two-stroke engine relies on a clean, fully functioning cooling system to deliver consistent power and prevent costly damage from overheating. Follow this MotoSport-exclusive guide for a smooth, effective coolant change tailored to your dirt bike.
What Makes Coolant Change Important for Your EC125?
- Prevents overheating – Fresh coolant maintains optimal thermal stability, especially during aggressive trail riding.
- Protects aluminum components – The EC125 cooling system uses aluminum radiators and components, which require corrosion-protective coolant, ideally a 50% mix of distilled water and ethylene glycol-based antifreeze with inhibitors for aluminum engines and radiators.
- Freezing protection – Essential if you encounter sub-zero riding conditions or store your bike during winter months.
Tools & Supplies Needed
- Phillips screwdriver or small socket set (for shrouds/guards)
- Drain pan for old coolant
- Fresh coolant – use a 50/50 mix of quality ethylene glycol-based coolant and distilled water (do not use tap water; it promotes corrosion)
- Shop rags
- Funnel
- Gloves and eye protection
Step-by-Step Coolant Change Procedure
- Let Your Bike Cool Completely
Never open the radiator cap when the engine is hot—wait until completely cooled to avoid dangerous scalds. - Remove Radiator Shrouds (If Necessary)
Use your screwdriver or socket to remove any plastic guards that obstruct the radiator cap or drain bolt. - Locate & Remove the Radiator Cap
Turn the radiator cap counterclockwise to open and relieve pressure. Place the motorcycle upright. - Drain Old Coolant
Find the small drain bolt near the bottom of the water pump or lower radiator hose. Place your drain pan underneath. Remove the bolt & gently tilt the bike as needed to empty all coolant. - Flush (Optional but Recommended)
For maximum cleanliness, flush with distilled water: reinstall the drain bolt, refill with distilled water, run engine briefly, then drain again. - Inspect System Elements
Check hoses, clamps, and radiator fins for wear. Do not use high-pressure water to clean radiator fins, which can damage them. - Add New Coolant
Mix coolant to a 50/50 ratio (if not premixed). Slowly refill through the radiator cap opening up to the marked level. This GAS GAS model typically uses about 0.7 liters, but always fill to the prescribed mark and avoid overfilling. - Bleed Air from the System
After refilling, run the engine briefly with the radiator cap off to help air bubbles escape. Watch for bubbling, wait until the thermostat opens and coolant level drops, then top off as needed and replace the cap securely. - Test Ride & Recheck Level
Take a short ride, let the bike cool, then double-check your coolant level. Add as needed. Watch for any leaks or abnormal temperature rise.
GAS GAS EC125-Specific Tips
- Coolant type – The factory fill may be colorless and opaque. Standard green or blue coolant is fine as long as it is suitable for aluminum and mixed properly.
- Regular inspection – Look out for leaks around hose clamps or the radiator after every coolant change.
- Spark plug care – Avoid spilling coolant on the tires or near the plug area—it can pose hazardous slipping risks.
- Operating conditions – For cold climates, ensure your coolant provides adequate freeze protection by using recommended mix ratios.
Signs It’s Time to Change Your Coolant
- Strange odors or discoloration in coolant
- Engine temperature fluctuations or overheating
- Visible debris, corrosion, or oily layer in the radiator
- Coolant more than 12 months old or after heavy racing season
Stay Cool and Ride with Confidence
Staying ahead of regular coolant changes and system checks ensures your GAS GAS EC125 remains trail-ready and keeps engine temperature in control whether you’re racing or trail riding. For specialist OEM and performance parts, trust MotoSport.
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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.