How to Change the Coolant in a 2023 Kawasaki KLX300SM
Shop parts for a 2023 Kawasaki KLX300SM Dirt Bike.
Regularly changing the coolant on your 2023 Kawasaki KLX300SM is crucial for precise temperature regulation, optimal power, and engine longevity. This supermoto offers lightweight performance with an efficient liquid-cooled engine – making maintenance especially important for aggressive street or dirt riding. Below is MotoSport’s step-by-step guide designed exclusively for KLX300SM owners.
What You Will Need
- Fresh motorcycle-safe coolant (silicate & phosphate free, not automotive antifreeze)
- 10mm socket and ratchet
- Phillips and/or flat screwdriver
- 8mm socket (for side panel access)
- Drain pan
- Funnel
- Distilled water (optional for flushing)
- Clean rag
- Protective gloves and eye protection
Steps to Change Coolant
- Ensure Engine is Cool: Allow your bike to completely cool down before beginning. Hot coolant can cause severe burns.
- Remove Body Panels: Use the 8mm socket to remove the left side panel, exposing the radiator cap and coolant reservoir.
- Position Drain Pan: Place it under the water pump (lower right side of the engine) to catch old coolant.
- Open Radiator Cap: Twist off the radiator cap slowly to release pressure. It is located on the top left side of the radiator.
- Remove Drain Bolt: Locate the 10mm drain bolt at the base of the water pump and carefully remove it. Let the coolant fully drain into your pan. To speed draining and help prevent vacuum lock, open the small bleeder screw on the opposite radiator end if applicable, using your screwdriver.
- Flush if Needed: For thorough maintenance, reinstall the drain bolt, refill the radiator with distilled water, and run the engine for a few minutes before draining again.
- Inspect Components: Check the old coolant for contaminants or discoloration. Inspect the radiator cap and hoses for cracks or deterioration – the KLX300SM’s exposed supermoto design makes hoses vulnerable to debris impacts.
- Replace Washers: Replace the drain bolt crush washer to avoid leaks.
- Add Fresh Coolant: Reinstall the drain bolt securely. Fill the radiator slowly with new coolant until full. Top off the overflow reservoir to the correct ‘Full’ line (visible through the semi-transparent tank behind the left side cover).
- Bleed Air: Lean the bike slightly side to side and gently squeeze coolant hoses to encourage trapped air out. Briefly start the bike with the radiator cap off, then top off if coolant level drops.
- Check for Leaks: Run the engine to operating temperature with the cap reinstalled. Check for leaks and monitor the reservoir; add coolant if the level drops after first use.
- Reinstall All Parts: Bolts should be snug but not over-tightened. Replace the side panel.
Special Notes for KLX300SM Owners
- The KLX300SM’s radiator hoses are typically more exposed than many dirt bikes due to its minimal supermoto bodywork. Consider installing an aftermarket skid plate or hose protectors if you ride on rough terrain or in traffic for added durability.
- Unlike carbureted KLX models, the 2023 KLX300SM features electronic fuel injection, providing a cooler, more consistent engine temperature but requiring cleaner coolant flow.
- Avoid overfilling the radiator; leave room for thermal expansion. Overfilled systems can spit coolant into the overflow after warmup.
Keeping your KLX300SM’s cooling system clean reduces engine stress, ensures consistent performance, and helps you get the most out of every ride—whether you’re carving asphalt or taking backroads. For replacement parts, upgraded coolant, or protective accessories, MotoSport has the full range of KLX300SM essentials.
Related Shopping Categories
Shop Radiators for a 2023 Kawasaki KLX300SM Dirt Bike.
Shop Coolant for a 2023 Kawasaki KLX300SM Dirt Bike.
Shop Temperature Sensors for a 2023 Kawasaki KLX300SM Dirt Bike.
Shop Tools for a 2023 Kawasaki KLX300SM Dirt Bike.
Shop Radiator Hoses for a 2023 Kawasaki KLX300SM 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.