How to Change the Coolant in a 2021 GAS GAS EX 450F: MotoSport.com Guide
Changing the coolant in your 2021 GAS GAS EX 450F is an essential part of upkeep to keep your engine performing at its best – particularly since these high-performance dirt bikes operate at elevated temperatures and often see aggressive riding conditions. This model, built on KTM-derived platform tech, uses a pressurized cooling system that requires attentive handling during maintenance. Follow the proprietary MotoSport step-by-step guide below for a robust and safe coolant replacement.
Supplies & Preparation
- Recommended coolant (consult your manual for correct type and mix ratio)
- Clean drain pan
- Rags and safety gloves
- Funnel
- Ratchet or socket to remove radiator guard and drain bolt
Note: Never open the cooling system or radiator cap when the engine is hot. Always work with a cold engine to prevent injury and avoid pressurized fluid spray. Secure your EX 450F upright and stable before beginning maintenance.
Step 1: Access the Cooling System
- Remove both radiator shrouds if needed for better access.
- Locate the radiator cap on the right side of the bike, near the steering head. Slowly turn it counterclockwise to release any residual pressure.
Step 2: Drain the Old Coolant
- Position the drain pan under the coolant drain bolt – typically located at the bottom of the water pump cover on the right engine case.
- Using a suitable socket, loosen and remove the drain bolt. The old coolant will begin to flow out; open the radiator cap fully to allow air to enter for complete drainage.
- Inspect the old coolant. Any milky oil or metallic debris may indicate internal engine issues requiring further attention.
Step 3: Flush (Optional, Recommended for Dirty Coolant)
- Reinstall the drain bolt temporarily.
- Fill the radiator slowly with distilled water.
- Reinstall the cap. Briefly start the engine (less than 30 seconds, no more) to circulate water, then repeat the draining process. This clears debris and residue from the system.
- Repeat until only clear water flushes out, then drain thoroughly and reinstall the drain bolt with a new washer if needed.
Step 4: Refill with Fresh Coolant
- Using a funnel, pour the new coolant slowly into the radiator until it reaches the base of the filler neck. Avoid mixing different types of coolant, as this can cause gelling or chemical reaction.
- Lightly squeeze both upper and lower radiator hoses to burp out trapped air bubbles as you fill. Stop periodically and top off as needed.
Step 5: Bleed & Check the System
- With the radiator cap off, briefly start the bike and let it idle until the thermostat opens – you may see the coolant level drop as bubbles escape. Top up coolant as necessary.
- Once the coolant remains stable at the filler neck, reinstall the radiator cap securely.
- Check both the radiator and overflow reservoir (if equipped) levels. Adjust the overflow bottle so it sits between MIN and MAX indicators.
Step 6: Inspect for Leaks & Top Off After Heat Cycle
- After your first ride post refill, allow the engine to cool completely and re-check the coolant level in both the radiator and reservoir. Top off as needed. Recheck for leaks or residue at hose clamps and the drain bolt.
Model-Specific Tips for GAS GAS EX 450F Owners
- The EX 450F cooling system capacity is tuned for aggressive trail and cross-country use. Always use high-quality, motorcycle-specific coolant for best corrosion resistance and freeze protection.
- Inspect radiator fins regularly for damage or debris – bent fins can be carefully straightened, and mud or sand buildup should be gently cleaned away to maximize cooling efficiency.
- Regular sand or muddy riding conditions may require more frequent coolant checks and radiator maintenance, as heavy deposits can impair airflow and cooling.
- If your coolant level repeatedly drops between rides, check for leaks or possible head gasket issues immediately.
By following MotoSport's step-by-step coolant change process, you'll protect your 2021 GAS GAS EX 450F's engine for miles of confident off-road performance.
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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.