How to Change the Coolant in a 2018 Yamaha YZ65

Shop parts for a 2018 Yamaha YZ65 Dirt Bike.

Regularly changing the coolant on your 2018 Yamaha YZ65 is vital for peak performance, preventing overheating, and extending engine life. This step-by-step MotoSport.com guide covers the entire coolant replacement process, with important model-specific notes for your YZ65.

Tools & Supplies Needed

  • Coolant compatible with aluminum engines (ready-to-use premixed formula recommended)
  • Drain pan
  • Socket wrench and correct size socket (for drain bolt)
  • Funnel
  • Clean rags
  • New crush washer or gasket (optional)
  • Fresh distilled water (for optional flushing step)

Coolant Replacement Procedure

  1. Ensure bike is completely cool: Never remove the radiator cap while the engine is warm or hot. Allow the engine and radiator to cool down completely to prevent injury from hot coolant or steam.
  2. Remove plastic components (if needed): You may need to remove shrouds or panels to easily access the radiator cap and drain bolt.
  3. Place drain pan: Position a drain pan under the engine area where the coolant drain bolt is located.
  4. Remove the radiator cap: Loosen the radiator cap slowly to relieve any residual pressure, then remove completely to allow air in.
  5. Remove coolant drain bolt: Locate the coolant drain bolt on the right side of the engine, usually near the bottom of the cylinder or water pump casing. Using a socket wrench, remove the drain bolt and let coolant flow into the drain pan.
    Tip: Check the crush washer or gasket. Replace if worn to ensure a leak-free seal on reassembly.
  6. Flush the cooling system (recommended): For maximum protection and to remove any old residue, pour distilled water into the radiator, reinstall the drain bolt, start the bike briefly, then drain and repeat until clear water flows out. Remove again the drain bolt and radiator cap to drain completely.
  7. Install drain bolt: Tighten the drain bolt to the specified torque (10 N·m, 7.4 lb·ft). Take careovertightening can strip the threads.
  8. Refill with coolant: Using a funnel, fill the radiator to the specified level with fresh coolant. Leave some room at the top—never overfill.
    On the YZ65, check the manufacturer's recommendation for coolant type and volume. Use coolant formulated for aluminum engines to prevent corrosion and maximize performance.
  9. Bleed the system: Gently rock the bike side to side and squeeze radiator hoses by hand to help remove any trapped air bubbles. Top off as needed.
  10. Reinstall the radiator cap: Double-check coolant level, then reinstall and securely tighten the radiator cap.
  11. Run the engine and check for leaks: Start the bike and let it idle for several minutes. Shut off and allow it to cool. Recheck the coolant level and top off if necessary. Inspect all hose connections and the drain bolt for leaks.
  12. Reassemble shrouds or panels: Replace any plastic components removed during the process.

Important 2018 Yamaha YZ65 Model Notes

  • This Yamaha 65cc engine is liquid-cooled with an aluminum cylinderproper coolant selection is crucial for corrosion protection and optimal heat transfer.
  • Flush periodically, not just annually: If you run in muddy or sand-heavy environments, or after overheating, flush the system thoroughly before refilling.
  • Monitor power reduction: Consistent loss of power or engine overheating can signal coolant issues or restricted flow. Address issues immediately to avoid expensive repairs.
  • Upgrades: Performance cylinder heads (such as billet or VHM style) help keep your YZ65 cooler during high-RPM use.

Maintenance Reminder

Check your coolant before every ride, and follow the maintenance schedule for replacement intervals. For specialized parts and racing upgrades, MotoSport.com carries everything you need to keep your 2018 Yamaha YZ65 running strong.

Related Shopping Categories

Shop Radiators for a 2018 Yamaha YZ65 Dirt Bike.

Shop Coolant for a 2018 Yamaha YZ65 Dirt Bike.

Shop Temperature Sensors for a 2018 Yamaha YZ65 Dirt Bike.

Shop Tools for a 2018 Yamaha YZ65 Dirt Bike.

Shop Radiator Hoses for a 2018 Yamaha YZ65 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.