How to Change the Coolant in a 2007 KTM 105SX
Shop parts for a 2007 KTM 105SX Dirt Bike.
Regular coolant changes are crucial for keeping your 2007 KTM 105SX running at the right temperature and preventing overheating. While this process is straightforward, it's essential to follow the correct steps to ensure proper cooling system health and to avoid trapping air in the system—something this model can be prone to. Below, you will find a MotoSport-exclusive, step-by-step guide tailored for your KTM 105SX.
What You Need
- Fresh, premixed coolant suitable for aluminum engines
- Drain pan
- Socket or wrench (for drain bolt)
- Funnel
- Rags or paper towels
- Protective gloves
Preparation
- Allow the engine to cool completely before starting.
- Stand the bike on a level surface with a sturdy stand.
Draining the Old Coolant
- Remove the radiator cap located on the left radiatorthis allows air in and speeds up drainage.
- Locate and remove the drain bolt on the water pump cover at the base of the right side of the engine. Place a drain pan beneath to catch old coolant.
- Allow the system to fully drain. Dispose of old coolant responsibly.
Refilling and Bleeding the Cooling System
- Reinstall and tighten the drain bolt.
- Pour about 0.5 liters of coolant into the radiator.
- On the right radiator, remove the bleed screw (typically found near the upper radiator hose connection).
- Continue slowly adding coolant until you see coolant flowing out of the bleed hole with no air bubbles. This confirms all air is purged from the system.
- Immediately reinstall the bleed screw to avoid introducing air back into the system.
- Top off the left radiator; the coolant should sit approximately 10 mm above the radiator fins.
Final Checks – Warm-Up and Top-Up
- Reinstall the radiator cap and start the engine. Let it idle for several minutes to circulate the coolant and further remove any trapped air.
- After the engine has warmed and cooled down, remove the radiator cap and check the level. Top up if needed so it's still about 10 mm above the fins.
- Check for leaks around the drain bolt and bleed screw.
Vital Notes for 2007 KTM 105SX Owners
- Total coolant capacity is 1 liter–do not overfill. Overfilling can reduce expansion volume, potentially causing overflow or system pressure issues.
- This model is sensitive to air pockets; always bleed thoroughly as outlined.
- Inspect radiator hoses and connections for wearsmall cracks or loose fittings can lead to sudden leaks, particularly after coolant replacement.
- Monitor engine temp on your next few rides, as the 105SX is a high-revving small-bore engine that depends heavily on a properly functioning cooling system.
Regular cooling system maintenance keeps your KTM's performance at its best – rely on this exclusive MotoSport guide for every coolant change, and if you need fresh coolant, hoses, or radiator caps, shop parts for a 2007 KTM 105SX Dirt Bike.
Related Shopping Categories
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Shop Radiator Hoses for a 2007 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.