How to Change the Coolant in a 1993 Kawasaki KX125
Shop parts for a 1993 Kawasaki KX125 Dirt Bike.
Routine coolant changes are essential for keeping your 1993 Kawasaki KX125 running cool in the harshest racing environments. The KX125's lightweight, high-revving two-stroke engine generates significant heat–neglected coolant maintenance can lead to premature wear or even catastrophic damage. Follow this MotoSport-exclusive step-by-step guide to safely change the coolant while minimizing mess and ensuring optimal cooling performance.
What You'll Need
- Socket wrench (8mm for the KX125 coolant drain bolt)
- Drain pan
- Fresh coolant (pre-mixed for dirt bikes; Engine Ice and similar products work well)
- Distilled water (for flushing)
- Funnel
- Shop towels
- Protective gloves (recommended)
Important: Safety First.
Only change the coolant when the engine is completely cool. Hot coolant can cause severe burns. Spilled coolant is slippery–keep it off tires and clean up any residues immediately. Dispose of old coolant according to local regulations; do not pour it down drains or onto the ground.
Step-by-Step Instructions
- Preparation
- Ensure the bike is on a level surface and the motor is cold.
- Remove the seat and side plastics if easier access to the radiator cap and hoses is needed.
- Remove the Radiator Cap
- Push down and twist the radiator cap to release it–this equalizes system pressure and allows coolant to drain freely.
- Drain the Old Coolant
- Locate the coolant drain bolt at the bottom of the water pump (right side of the engine case).
- Place your drain pan under the bolt and carefully loosen with your 8mm wrench.
- Allow the old coolant to completely drain into the pan.
- If desired, gently tilt the bike to ensure thorough drainage.
- Flush the Cooling System (Recommended)
- Reinstall the drain bolt loosely.
- Pour distilled water into the radiator to flush out remaining old coolant and debris.
- Remove the drain bolt again and allow all water to escape.
- Repeat until expelled water runs clear for best results.
- Reinstall the Drain Bolt
- Tighten the drain bolt securely. Do not overtighten, as the threads in the aluminum case can easily strip on older KX models.
- Add New Coolant
- Using a funnel, slowly pour pre-mixed dirt bike coolant into the radiator. Fill to the base of the filler neck.
- Tap or gently squeeze radiator hoses with your hand to release trapped air bubbles.
- Bleed the System
- Start the bike briefly without the radiator cap, allowing it to idle and burp out air.
- Watch for air bubbles escaping from the radiator neck; top off as needed during this process.
- Replace the radiator cap securely.
- Final Check
- Inspect for leaks around the drain bolt and radiator hoses.
- Double-check the coolant level after your first ride, as small air pockets can work their way out on initial use.
KX125 Owner's Notes & Model-Specific Tips
- The 1993 KX125 was known for its aggressive, high-RPM powerband and lightweight chassis, both of which put extra thermal stress on the engine and cooling system.
- With older KX models, pay attention to brittle hoses or corroded clamps. Original 1993 parts may be overdue for replacement, so inspect and consider fresh radiator hoses and caps for peace of mind.
- Only use coolants safe for aluminum and magnesium engines; never use standard automotive coolant containing silicates, which can damage internal passages in dirt bike radiators.
- The KX125's compact layout means spills are more likely to reach tires or brakes–be diligent with cleanup.
Keeping your 1993 KX125's coolant fresh ensures your legendary two-stroke stays cool lap after lap, protecting your investment and maximizing riding time. Don't forget to stock up on quality maintenance parts, gaskets, and coolants to make every service as hassle-free as possible.
Related Shopping Categories
Shop Radiators for a 1993 Kawasaki KX125 Dirt Bike.
Shop Coolant for a 1993 Kawasaki KX125 Dirt Bike.
Shop Temperature Sensors for a 1993 Kawasaki KX125 Dirt Bike.
Shop Tools for a 1993 Kawasaki KX125 Dirt Bike.
Shop Radiator Hoses for a 1993 Kawasaki KX125 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.