How to Change the Coolant in a 2006 KTM 105SX
Shop parts for a 2006 KTM 105SX Dirt Bike.
Proper cooling system maintenance keeps your 2006 KTM 105SX performing at its best – whether you're hitting the track or trails. Changing the coolant is a key part of this, preventing overheating and safeguarding the engine. The 105SX features a compact, high-revving two-stroke engine, making proper cooling especially critical for consistent power delivery and engine longevity.
What Makes the 2006 KTM 105SX Cooling System Unique?
- It uses a relatively small total coolant capacity: 1L.
- Coolant bleeding is performed through a specific bolt on the right-side radiator.
- Always refill and bleed carefully: trapped air will cause overheating or poor performance.
- Check the coolant level after every ride, especially after a flush.
How to Change the Coolant – Step by Step Guide
-
Preparation & Safety
Make sure the engine is completely cool before starting. Place the bike on a stand or securely supported surface. Wear gloves and eye protection to avoid contact with old coolant, which is toxic. -
Drain the Old Coolant
- Remove the radiator cap (located on top of the left radiator).
- Place a drain pan beneath the engine. Loosen the lower water pump bolt to drain the coolant from the system.
- Let all coolant drain fully.
Note: Dispose of used coolant responsibly – never pour it down drains. -
Flush the System (Optional but Recommended)
- If coolant appears dirty or the bike has overheated, fill the radiator with distilled water, reinstall the drain bolt, and run the engine briefly.
- Drain again for a thorough flush. -
Refill with New Coolant
- Pour approximately 0.5 liters of new, high-quality motorcycle coolant into the radiator.
- Locate and remove the bleed screw on the right-side radiator.
- Continue adding coolant until it emerges free of bubbles from the bleed screw – this ensures air pockets are purged.
- Immediately reinstall the bleed screw tightly to prevent air re-entering. -
Top Off and Final Bleeding
- Add coolant in small increments to the left radiator until the fluid sits about 10 mm above the radiator fins.
- Reinstall the radiator cap.
- Start the bike and let it idle for a few minutes, watching for leaks while rocking the bike side to side to help dislodge any remaining air.
- Shut off the engine and let cool. Recheck coolant level and top off if necessary. -
Check After Your Next Ride
- After a short, gentle test ride, let the engine cool and inspect the coolant level again.
- Make sure there are no leaks and fluid remains at the correct height.
- Monitor coolant level and repeat the bleed if needed for best reliability.
Important Tips for 105SX Owners
- Always use recommended motorcycle-specific coolant – never use straight tap water as it can cause corrosion and cooling inefficiency.
- Inspect radiator hoses and clamps for wear or leaks during coolant changes to prevent future issues.
- This model's radiator cap and bleed screw are easy to access, but overtightening can cause damage – tighten only to specified torque.
- Air in the system is the #1 cause of overheating after a coolant change. Always take time to bleed thoroughly.
- Check and maintain throttle cable free play (3–5 mm) as part of routine maintenance for optimal throttle response.
Related Shopping Categories
Shop Radiators for a 2006 KTM 105SX Dirt Bike.
Shop Coolant for a 2006 KTM 105SX Dirt Bike.
Shop Temperature Sensors for a 2006 KTM 105SX Dirt Bike.
Shop Tools for a 2006 KTM 105SX Dirt Bike.
Shop Radiator Hoses for a 2006 KTM 105SX 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.