How to Change the Coolant in a 2021 Husqvarna FE350S

Shop parts for a 2021 Husqvarna FE350S Dirt Bike.

Routine coolant maintenance on your 2021 Husqvarna FE350S is critical for performance and engine longevity–especially for off-road riding where heat management is key. Use this exclusive MotoSport step-by-step guide for a complete coolant change, tailored specifically for the FE350S.

Tools and Supplies Needed

  • Coolant compatible with aluminum engines (ready-to-use or pre-mixed)
  • Socket set, including 10 mm (for water pump cover bolt)
  • Catcher tray for old coolant
  • Funnel
  • Shop rags
  • Distilled water (if you want to flush the system)
  • Safety gloves and glasses

Step-by-Step Coolant Change Process

  1. Ensure the motorcycle is cool and secure. Stand the FE350S upright on a level surface before starting. Never open the radiator cap on a hot engine–danger of burns from pressurized coolant.
  2. Remove the radiator cap. This releases pressure from the system. The radiator cap is located at the top of the left radiator, above the radiator fins.
  3. Locate and remove the water pump cover drain bolt. Place your catch tray beneath the water pump. The drain bolt is typically a 10 mm bolt at the bottom of the water pump cover on the right side of the engine. Remove it and allow all coolant to drain out completely.
  4. Flush with distilled water (optional but recommended). Reinstall the drain bolt temporarily, fill the system with distilled water, run the engine briefly, then drain again to clear out any remaining old coolant or debris. Repeat if necessary for extreme contamination.
  5. Reinstall the drain bolt. Clean the bolt threads, install a new seal ring if available, and tighten the water pump cover screw to 10 Nm (7.4 lbf ft). Proper torque prevents leaks.
  6. Refill with new coolant. Using a funnel, fill the radiator slowly with your chosen coolant until it is just below the top of the fill neck or as specified by the owner's manual. Squeeze radiator hoses lightly to help dislodge air.
  7. "Burp" the cooling system. With the radiator cap off, start the engine and let it idle for a minute or two. Watch the coolant level and top up as needed. This helps remove air pockets.
  8. Reinstall the radiator cap securely. Double-check coolant level one more time before replacing the cap.
  9. Clean any spilled coolant thoroughly. Coolant is toxic to pets. Make sure nothing is left on the bike or floor.
  10. Test ride and recheck. After a short ride, let the engine cool and recheck the coolant level, topping up if necessary.

Things FE350S Owners Should Know

  • The 2021 FE350S has a high-performance DOHC engine, making cooling system health critical in hard enduro or dual sport riding.
  • Some models include a cooling fan kit–ensure yours is working properly, especially for slow, technical terrain that can cause overheating.
  • The emissions system (including the charcoal canister and related valves) is unique to street-legal FE350S variants. If you have removed emissions equipment, ensure all cooling lines and block-off plugs are properly installed to prevent air leaks that can affect cooling and performance.
  • Use only coolants safe for magnesium and aluminum engine components. Avoid mixing coolant brands or types unless they are specifically marked as compatible.

Maintaining your cooling system on the 2021 Husqvarna FE350S is straightforward–but it's an essential part of keeping your dual sport ready for the next ride. For factory-spec coolant, robust radiators, hoses, or upgrade kits, MotoSport carries everything you need to keep your FE350S in peak condition.

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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.