How to Change the Coolant on a 2020 Beta 125 RR

Shop parts for a 2020 Beta 125 RR Dirt Bike.

Routine coolant changes preserve the performance and longevity of your 2020 Beta 125 RR two-stroke. Unlike older model Betas, the 2020 125 RR omits the radiator bleeder screw, and it's essential to properly purge air from the system after replacement. Here is a step-by-step, MotoSport-exclusive guide for a clean, safe, and thorough coolant change.

Essential Tools & Supplies

  • Coolant compatible with aluminum engines (pre-mixed recommended)
  • Basic hand tools (socket set, flat screwdriver, pliers)
  • Drain pan and shop towels
  • Protective gloves and eye protection

Preparation

  • Allow the engine to fully cool – never remove the radiator cap when hot as pressure can cause burns.
  • Position the bike upright, supported securely on a stand.

Draining the Coolant

  • Locate the coolant drain bolt, typically at the lowest point of the water pump cover on the right side of the engine.
  • Place the drain pan beneath the drain bolt.
  • Remove the radiator cap to relieve any residual pressure.
  • Loosen and remove the drain bolt; allow coolant to fully drain.
  • Inspect the drain bolt and replace its sealing washer if necessary.
  • Reinstall and torque the drain bolt securely.

Flushing (Optional but Recommended)

  • If the coolant is contaminated, flush with distilled water by reinstalling the drain bolt, refilling with distilled water, running the engine briefly, shutting off, draining, and repeating until clear. Do not leave tap water inside due to mineral build-up risk.

Filling the Cooling System

  • Slowly fill the radiator with fresh coolant to avoid air pockets.
  • Rock the bike side to side gently to encourage trapped bubbles to rise.
  • With no bleeder screw (as found on pre-2020 Betas), the rocking method is necessary for air evacuation.
  • Continue filling until coolant level sits just above the radiator core fins.
  • Reinstall the radiator cap securely.

Burping the System & Final Check

  • Start the engine and let idle until it reaches full operating temperature.
  • Shut it off, allow to cool, and recheck the coolant level.
  • If necessary, top off as required and reinstall cap.
  • Check for leaks at drain bolt and hoses.

Special Notes for 2020 Beta 125 RR Owners

  • No radiator bleeder screw: Air must be burped by rocking the bike – neglecting this step can lead to overheating and engine damage.
  • Proper coolant volume: Fill until coolant sits right above the radiator fins; overfilling can cause overflow during operation.
  • Environment & safety: Never dispose of old coolant down drains or onto soil. Handle according to local regulations.

When To Replace Coolant

  • At least once a year or after significant muddy riding, as recommended by maintenance best practices.

MotoSport is your source for factory-approved parts, fluids, and maintenance solutions to keep your Beta at its best.

Related Shopping Categories

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Shop Radiator Hoses for a 2020 Beta 125 RR 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.