How to change the coolant in a 1998 KTM 200EXC Dirt Bike

How to Change the Coolant in a 1998 KTM 200EXC

Shop parts for a 1998 KTM 200EXC Dirt Bike.

Changing the coolant is essential maintenance for your KTM 200EXC, keeping the engine running at the proper temperature and preventing corrosion in the cooling system. The 1998 KTM 200EXC uses a conventional two-stroke liquid cooling system with a water pump and dual radiators. While the procedure is straightforward, it's important to follow the correct steps and pay attention to details that matter for this specific model year.

What You Need

• New coolant (use a high-quality motorcycle-specific coolant, mixed 40% antifreeze to 60% distilled water, unless using a premix)
• 10 mm wrench or socket
• Drain pan
• Clean shop rags
• Funnel (for refilling)
• Torque wrench (recommended)
• Protective gloves (recommended)

Step-by-Step Coolant Change Procedure

• 1. Ensure the motorcycle is cold and upright.
  For safety, only work on a cold engine to avoid burns or high pressure in the system. Place the bike securely on a stand so it sits level.
• 2. Remove the radiator cap.
  Locate the radiator cap at the top of the left radiator. Slowly twist it open to relieve any remaining pressure. Removing the cap before draining allows the coolant to flow out completely.
• 3. Place a drain pan under the water pump cover.
  On the right side of the engine, find the 10 mm drain bolt at the bottom of the water pump cover. Position your drain pan to catch the coolant.
• 4. Remove the water pump drain bolt.
  Using a 10 mm wrench or socket, carefully remove the bolt and allow all coolant to drain fully from the system. Wipe away any spilled fluid. Inspect the copper drain plug washer and replace if damaged, as leaks are common on older two-strokes if this isn't resealed properly.
• 5. Reinstall and torque the drain bolt.
  Once dripping has stopped, reinstall the bolt. The recommended torque is 15 Nm (11.1 lbf-ft) for the drain plug. Do not overtighten or you may damage the cover.
• 6. Fill the radiator with fresh coolant.
  Insert a funnel into the radiator neck. Slowly pour new coolant to the specified level – fill just till the fluid covers the top of the radiator core fins when the bike is upright. Avoid overfilling.
• 7. Bleed the cooling system (if equipped with a bleed screw).
  Gently tip the bike or carefully squeeze the radiator hoses to help release any trapped air. Some models have a bleed screw on the radiator – if so, briefly open it until coolant runs out bubble-free, then retighten.
• 8. Reinstall the radiator cap securely.
  Make sure the seal is clean and seats properly to prevent leaks or air entry.
• 9. Start the engine and inspect for leaks.
  Run the bike at idle for several minutes. Watch the coolant level through the radiator neck (with cap off initially) and top up if necessary. Check for leaks around drain and hose connections.

Special Tips for 1998 KTM 200EXC Owners

• Original radiator and water pump gaskets: At this age, many gaskets may be brittle. Consider replacing the water pump O-ring and radiator cap seal if you notice any seepage.
• Plastic impellers: 98-00 KTM 200EXCs may have plastic water pump impellers which can degrade. Inspect for cracks during coolant changes. Consider upgrading to a performance metal impeller for improved flow and longevity.
• Coolant change interval: KTM recommends changing coolant every year, or sooner if the bike has seen heavy use or overheating, to maintain anti-corrosion protection.
• Mixing coolant types: Never mix silicate-based automotive coolant with motorcycle or propylene glycol-based formulas. Use only the recommended type for two-stroke cooling systems.

Expanding the life of your KTM 200EXC's engine starts with routine maintenance, and coolant changes are a critical part of keeping your dirt bike ready for every ride.

Related Shopping Categories

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Shop Radiator Hoses for a 1998 KTM 200EXC 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.