How to Change the Coolant in a 2017 KTM 150SX – A MotoSport Guide
Shop parts for a 2017 KTM 150SX Dirt Bike.
Changing the coolant on your 2017 KTM 150SX is a key maintenance task that keeps your engine running cool and protected under even the most intense riding conditions. Here’s the exclusive MotoSport guide to draining and replacing coolant on this two-stroke powerhouse, including specific tips to help you avoid common pitfalls and keep your 150SX performing at its best.
Things You’ll Need
- Drain pan or suitable container
- 8mm socket or wrench
- Fresh coolant (engine ice or approved motorcycle coolant, not standard automotive types)
- Funnel
- Clean rags
- Torque wrench (recommended for reinstalling bolts)
- Gloves and goggles for safety
Before You Begin
- Always allow the engine to fully cool before opening the radiator. Opening a hot system can cause dangerous coolant spray and burns.
- Make sure your work area is well-ventilated and that all used coolant is properly disposed of at a recycling center. Never pour coolant down the drain or on the ground.
Coolant Change Procedure
- Remove seat and bodywork as needed to access the top of the radiator. This isn’t always required, but it makes the job easier and less messy.
- Open the radiator cap slowly to release any residual pressure. The cap sits at the top of the left-side radiator, easily accessible on the 150SX.
- Locate the coolant drain bolt. On the 2017 KTM 150SX, this is typically an 8mm bolt on the water pump cover, located at the lower right-side of the engine.
- Place the drain pan underneath the water pump and remove the drain bolt. Allow the coolant to flow out completely. To speed draining, gently tip the bike from side to side.
- Inspect the old coolant for any sludge or contamination. This can point to internal issues such as head gasket leaks or corrosion.
- Reinstall and snug the drain bolt (don’t overtighten; if possible, use a torque wrench set to manufacturer spec).
- Fill the radiator with fresh coolant. Use a funnel to prevent spills. Fill up to the base of the radiator neck.
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Bleed air from the system:
- With the radiator cap off, gently rock the bike or squeeze the radiator hoses to help trapped air escape.
- Once bubbles stop appearing, top off as needed.
- Replace radiator cap firmly and clean up any spilled coolant.
- Start the engine and let it reach full temperature with the bike securely parked. Monitor for leaks and verify that the coolant level remains stable.
Model-Specific Notes for the KTM 150SX
- The 2017 KTM 150SX is a high-revving two-stroke, meaning proper cooling is critical. Overheating can quickly damage the piston and cylinder plating, which is an expensive repair.
- The 150SX has a relatively simple cooling system. Still, radiator fins can become clogged with mud or bent, hurting efficiency. Straighten and clean fins during every coolant change.
- If you ride in extreme mud or sand, install a sand or dust cover on the air filter and clean the cooling system more frequently.
- Change the radiator cap periodically if it shows any signs of failing to hold pressure.
Helpful Tips
- Always use coolants designed for motorcycle use, and avoid mixing brands unless identical specifications are guaranteed.
- Check the water pump and hose clamps for leaks each time you service the system.
- Dispose of old coolant safely – used coolant is toxic to pets and wildlife.
Regular coolant changes — at least every season or sooner if you ride hard or in demanding conditions — will extend engine life and help you get the most from your KTM 150SX. For any replacement hoses, radiator caps, or other cooling system components, shop parts for a 2017 KTM 150SX Dirt Bike.
Related Shopping Categories
Shop Radiators for a 2017 KTM 150SX Dirt Bike.
Shop Coolant for a 2017 KTM 150SX Dirt Bike.
Shop Temperature Sensors for a 2017 KTM 150SX Dirt Bike.
Shop Tools for a 2017 KTM 150SX Dirt Bike.
Shop Radiator Hoses for a 2017 KTM 150SX 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.