How to Change the Coolant in a 2024 GAS GAS EX 300
Changing the coolant on your 2024 GAS GAS EX 300 is essential for keeping the engine running cool – especially during demanding rides. This guide walks you through every step specific to your bike, with tips to make the process smooth and safe.
Before You Begin
- Allow the engine and radiators to fully cool. Working with a hot system risks burns and damage.
- Gather necessary tools and supplies: suitable coolant (consult your manual or use a top-quality premix for aluminum engines), a drain pan, socket set, and a clean funnel.
- Work in a well-ventilated area and dispose of old coolant responsibly.
Step 1 – Access the Cooling System
- Secure the bike upright on a stand.
- Remove the seat and, if needed, the fuel tank shrouds to give clear access to the radiator cap and coolant system.
- Locate the radiator cap positioned on the top of the left radiator. Do not open while hot – always wait until it is completely cool.
Step 2 – Drain the Old Coolant
- Position your drain pan underneath the water pump area on the right side of the engine.
- Locate the coolant drain bolt at the bottom of the water pump cover.
- Using a socket, loosen and remove the drain bolt. Let all coolant flow into the pan.
- Remove the radiator cap. This allows air in, letting coolant drain fully from both radiators.
- Inspect the removed coolant for debris or oil contamination. If present, investigate before reassembly.
Step 3 – Flush (Recommended)
- Replace the drain bolt temporarily and loosely.
- Pour distilled water into the radiator neck until full. Reinstall the cap and briefly start the engine for 10–20 seconds. Shut off, remove the cap, and drain again. This clears residual old coolant or contaminants.
- Once drained, securely reinstall the drain bolt with a new sealing washer if required. Tighten to factory torque spec.
Step 4 – Refill with New Coolant
- Check your owner manual for coolant capacity and type. Use a high-quality, silicate-free coolant or recommended premix for aluminum systems (usually a 50/50 mix).
- Slowly pour coolant into the radiator neck until nearly full. Tilt the bike side to side gently to help trapped air escape.
- Let coolant settle, then top off to just under the lip of the fill neck.
Step 5 – Bleed & Final Check
- Reinstall the radiator cap completely.
- Start the bike and let it idle for several minutes. Watch for leaks and monitor temperature. As the thermostat opens, trapped air should burp out – occasionally revving gently can help dislodge bubbles.
- Shut off and let cool. Check coolant level: it may drop as air escapes. Top off if needed.
- Inspect the entire cooling system for leaks, especially around the drain bolt and hoses.
Model-Specific Notes & Tips
- The GAS GAS EX 300 shares similar systems with KTM and Husqvarna 2-strokes, but always confirm part compatibility and specs for the GAS GAS version.
- Radiator cap is specific: Be sure to reinstall it properly to maintain the correct pressure.
- Annual or biannual coolant changes are recommended, even with premix coolants, to prevent corrosion and overheating.
- If your EX 300 is frequently ridden in extremely hot or cold conditions, check with your MotoSport tech on the best coolant mixture ratio.
Maintenance Reminder
- Monitor coolant after your first ride post-change. Top off if any air escapes and level drops.
- Keep an eye on engine temperature and venting – persistent overheating may indicate other issues needing attention.
With proper care, your 2024 GAS GAS EX 300 will stay reliable and cool – ready for every ride.
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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.