How to Change the Coolant in a 2021 Sherco 300 SE FACTORY

Shop parts for a 2021 Sherco 300 SE FACTORY Dirt Bike.

Routine coolant changes are essential to keep your 2021 Sherco 300 SE FACTORY running at peak temperature and to protect your engine from corrosion and overheating. This unique enduro model features a performance-oriented design, making timely maintenance especially important for riders who push their bikes in challenging off-road conditions. Follow this exclusive MotoSport.com guide for best results.

What You Need

  • Fresh coolant compatible with aluminum motorcycle radiators
  • 10 mm socket
  • Drain pan
  • Funnel
  • Rags
  • Torque wrench (capable of 6 Nm and 10 Nm)
  • Safety gloves & goggles

Step 1: Allow the Engine to Cool

Before you begin, make sure your engine is completely cool to avoid burns and ensure safe handling.

Step 2: Access the Cooling System

  • Remove the seat to access the radiator area.
  • If needed for easier access, disconnect the battery and remove the fuel tank and radiator side covers.

Step 3: Drain the Old Coolant

  • Place your drain pan beneath the right side of the engine.
  • Locate the coolant drain bolt (reference screw A in your engine manual) situated on the water pump cover.
  • Using a 10 mm socket, slowly loosen and remove the drain screw to allow the old coolant to flow out.
  • Carefully remove the radiator cap to ensure complete drainage.
  • If your bike is equipped with a coolant overflow reservoir, drain and rinse it as well.

Step 4: Inspect Components

  • Check radiator hoses for cracks, stiffness, or chafing. Replace any worn hoses.
  • Inspect hose clamps to confirm they are present and intact.
  • Look at the radiator fins for any damage; gently straighten bent fins if necessary.

Step 5: Reinstall the Drain Bolt

  • Wipe the drain area clean.
  • Reinstall and tighten the drain bolt to a torque of 6 Nm to prevent leaks.

Step 6: Refill with Fresh Coolant

  • Insert a funnel into the radiator neck.
  • Slowly pour in the new coolant until it reaches the top of the radiator fill neck.
  • Recap the radiator securely.

Step 7: Bleed the Cooling System

  • Start the engine and let it idle for several minutes to circulate the coolant and release any trapped air.
  • As the engine warms, gently rock the bike side to side or squeeze radiator hoses to help purge air bubbles.
  • Shut off the engine and let it cool. Recheck the coolant level and top off as needed.

Step 8: Final Checks and Reassembly

  • Examine the water pump and drain areas for any leaks.
  • Reinstall the fuel tank, battery, and plastics if removed.
  • Double-check that all fasteners are tightened to specification: water pump housing screws to 10 Nm, drain plug to 6 Nm.

Important Notes for 2021 Sherco 300 SE FACTORY Owners

  • This model features a high-performance cooling system designed for extreme enduro. Keep coolant changes every two seasons or sooner under hard use.
  • If you ever see coolant leaking from the water pump weep hole, that indicates a worn seal–replacement requires clutch housing removal. Always use a new gasket and o-ring seal during reassembly to prevent leaks.
  • Factory torque specs are critical for avoiding damage to threaded components.

Stay on top of regular fluid changes to ensure your 2021 Sherco 300 SE FACTORY keeps performing at its best–on and off the trail.

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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.