How to Change the Coolant in a 2012 Husqvarna WR300

Shop parts for a 2012 Husqvarna WR300 Dirt Bike.

Changing the coolant in your 2012 Husqvarna WR300 is a critical maintenance task that ensures your two-stroke stays running cool and crisp, wheeling through the toughest trails and fastest track laps. The WR300, known for its power delivery and reliability, uses a traditional liquid cooling system that benefits from periodic service. This step-by-step guideunique to MotoSportcovers every detail to help you get it right the first time.

Tools – Supplies Needed

  • Correct coolant (pre-mixed or mixed with distilled water, never tap water for mixing)
  • Basic hand tools (socket wrench, flathead screwdriver)
  • Drip pan or container
  • Funnel
  • Protective gloves & goggles
  • Shop towels or rags

Steps to Change Coolant

  1. Preparation:
    Begin with a cold engine to avoid burns. Place the bike on a stand so it is secure and level.
  2. Radiator Cap Removal:
    Locate and remove the radiator cap from the left-hand side. This relieves pressure and allows coolant to drain freely.
  3. Drain Old Coolant:
    Position your drain pan beneath the water pump or lower radiator hose. On the WR300, the coolant drain bolt is typically located at the water pump cover. Loosen (and completely remove) the drain bolt. Allow all coolant to drain out—this should take just a few minutes.
  4. Flush the System (optional but recommended):
    For optimal results, flush the radiator with distilled water to remove any old coolant or debris. Replace the drain bolt, fill the system with distilled water, reattach the cap, run the bike briefly, then drain again. Repeat once if the rinse water is cloudy.
  5. Reinstall Drain Bolt:
    Inspect or replace the sealing washer, then reinstall and tighten the drain bolt to factory spec (consult your service manual for torque settings).
  6. Fill With New Coolant:
    Using a funnel, pour the new coolant into the radiator neck, filling to the base of the filler neck. Use only coolant recommended for aluminum engines and never mix coolant types. A 50/50 premix (not straight concentrate) is appropriate for most conditions.
  7. Burp the System:
    Air trapped in the system can cause overheating. With the bike upright, gently rock it side to side and front to backit helps dislodge bubbles. You may hear gurgling as air escapes. Slowly add a bit more coolant as the level drops†.
  8. Bleed and Top Off:
    Keep the cap off, start the engine, and let it idle for a few minutes. Briefly blip the throttle. Coolant level will drop as remaining air is released—add more coolant if needed. Once the engine reaches normal temperature, shut it down and let it cool fully. Top off to the base of the filler neck if necessary before reinstalling the cap.
  9. Check Coolant Reservoir (if equipped):
    The WR300 may not have a separate overflow tank, but if so, fill it to the upper line.
  10. Reassemble:
    Reinstall any removed plastics or guards.
  11. Dispose of Old Coolant Properly:
    Take the used coolant to an appropriate recycling center.

Specific Notes for the 2012 Husqvarna WR300 Owner

  • Aluminum Cooling System: Always use a coolant safe for aluminum componentsmixing types (green vs. orange, ethylene glycol vs. propylene glycol) can cause gumming and corrosion.
  • Frequent Checks: The WR300's high-revving two-stroke engine works hard; inspect coolant level often between rides, especially if you ride tight, technical terrain.
  • Burping is Crucial: Air pockets are a known issue on 2-stroke Husqvarnas if not burped out properly. Rocking the bike and running it with the cap off are essential to prevent the dreaded "steam out" mid moto.
  • Sealing Washer: Replace the drain bolt sealing washer each time to avoid leaks.
  • Owner's Manual Reference: For torque specs and diagrams, your factory service manual remains the gold standard for any task on your WR300.

Taking the time to refresh your WR300's coolant ensures optimal performance, reliability, and engine longevity. For all your maintenance parts, trusted fluids, and performance upgrades, MotoSport is your partner on & off the track.

† The WR300's design often traps air; repeat rocking and checking during the refill process for best results.

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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.