How to change the coolant in a 2018 KTM 150XCW Dirt Bike

How to Change the Coolant in a 2018 KTM 150XCW: Step-by-Step Guide

Shop parts for a 2018 KTM 150XCW Dirt Bike.

Regularly changing the coolant in your 2018 KTM 150XCW helps keep your engine running cool during demanding off-road rides. This guide walks you through the process and highlights important model-specific notes every owner should consider.

What You Need

• Fresh coolant formulated for off-road motorcycles
• Distilled water (if flushing)
• Socket set or wrench
• Drain pan
• Gloves – coolant can irritate skin
• Funnel
• New sealing washer for the drain bolt (recommended)

Step 1 – Prepare the Bike

• Ensure the engine is completely cool before starting.
• Stand the KTM 150XCW upright using a bike stand for stability.

Step 2 – Remove the Radiator Cap

• Slowly remove the radiator cap to release any pressure in the cooling system. This allows the coolant to drain faster later in the process.

Step 3 – Locate & Remove the Coolant Drain Bolt

• Position your drain pan under the water pump area on the right side of the engine case.
• The coolant drain bolt on the 2018 KTM 150XCW is typically found on the water pump cover at the lowest point; check for a small bolt with a copper or aluminum washer.
• Loosen and remove this bolt, allowing the coolant to drain completely.
• Once flow slows, rock the bike side to side to empty both radiators fully—the design of KTM's twin radiators means tilting can help clear trapped coolant.

Step 4 – Inspect & Replace the Sealing Washer

• Inspect the sealing washer on the drain bolt for wear or deformation; replace if necessary to ensure a tight seal and prevent future leaks.

Step 5 – (Optional) Flush the Cooling System

• If the coolant appeared dirty or you're switching coolant types, flush the radiators with distilled water.
• Reinstall the drain bolt, fill the radiator with distilled water, run the engine briefly, then drain and repeat until the water runs clear.

Step 6 – Reinstall the Drain Bolt

• Reinstall the cleaned drain bolt, using a new washer if recommended. Tighten it appropriately, but do not over-torque.

Step 7 – Add New Coolant

• Using a funnel, slowly fill the radiators with fresh coolant until the level reaches the bottom of the filler neck.
• KTM recommends a 50/50 mix of coolant and distilled water for optimal performance and protection.
• Install the radiator cap securely.

Step 8 – Bleed Air & Recheck Level

• Start the engine and let it run until warm. Squeeze the coolant hoses gently to help release air pockets.
• Turn off the engine, allow it to cool, and recheck the coolant level. Top off as needed.

KTM 150XCW Notes & Tips

• Model-specific note: The 2018 150XCW shares architecture with the larger two-stroke KTMs but has a smaller, high-revving engine. Proper cooling is essential, especially for riders in tight trails or slow situations where less airflow passes through the radiators.
• KTM's radiator caps can wear with frequent removal—inspect for a good seal every service.
• If your ride frequently overheats, consider checking the operation of the thermostat and the condition of the radiator hoses. Aftermarket solutions (such as radiator braces or upgraded hoses) are available and can extend longevity, especially for aggressive trail riding.
• Monitor for leaks or weepage around the drain bolt and water pump. Always replace any worn seals during routine maintenance.

Final Check

• Visually inspect the system for leaks. Dispose of the old coolant responsibly.
• After the first ride, recheck coolant level once the engine is cold to ensure it remains topped off.

Keeping your KTM 150XCW's cooling system in top shape is essential for reliable performance on every ride – from weekend trails to competitive enduro. Happy wrenching.

Related Shopping Categories

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Shop Radiator Hoses for a 2018 KTM 150XCW 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.