How to Change the Coolant in a 2021 Beta 125 RR Race

Shop parts for a 2021 Beta 125 RR Race Dirt Bike.

Changing the coolant on a 2021 Beta 125 RR Race is essential to keep your engine running cool and efficiently, especially with the robust 2-stroke powerplant and advanced race tuning unique to this model. Below is a proprietary MotoSport guide ensuring a proper coolant service for your Beta 125 RR Race.

What You'll Need

  • Coolant suitable for aluminum engines (Beta recommends using a high-quality, premixed motorcycle coolant)
  • Basic hand tools (socket wrench set, screwdrivers)
  • Catch pan for old coolant
  • Funnel
  • Shop rags
  • Protective gloves and eyewear

Step-by-Step Coolant Change Process

  1. Preparation
    - Make sure the engine is completely cool to avoid burns.
    - Place your bike on a level stand and remove the skid plate if required for access to the drain bolt.
  2. Access the Radiator and Drain
    - Remove the right radiator shroud by loosening the relevant fasteners.
    - Locate the coolant drain bolt on the lower water pump cover (right side of the engine).
    - Position a catch pan beneath the drain.
    - Slowly unscrew the radiator cap to release residual pressure.
    - Remove the drain bolt and allow all the coolant to drain out. Dispose of coolant in accordance with local environmental regulations.
  3. Flush (if desired)
    - If the coolant appears dirty or contaminated, flush the system by refitting the drain bolt, filling the radiator with distilled water, and running the bike briefly (1–2 minutes).
    - Drain again to remove water and debris.
  4. Reinstall Drain Bolt
    - Clean the drain bolt threads.
    - Install with the manufacturer's recommended torque spec (generally 10 Nm for the Beta 125 RR Race series water pump cover bolts)*.
  5. Refill with Coolant
    - Using a funnel, pour in the new coolant through the radiator neck until the fluid sits just above the core.
    - On the Beta 125 RR Race, there is no separate bleeder screw for air removal (unlike older generations, 2020 and later models rely on careful rocking and venting through the radiator neck)*.
  6. Bleed the System
    - Gently rock the bike from side to side to help trapped air escape.
    - Top off coolant again if it drops as the coolant settles.
    - Reinstall radiator cap securely.
  7. Start and Check
    - Start the engine, let it come to operating temperature, then allow it to cool completely.
    - Recheck coolant levels in the radiator and reservoir, topping off as needed.
    - Inspect for any sign of leaks at the drain bolt, radiator, or hoses.

Beta 125 RR Race Model-Specific Notes

  • The 2021 Beta 125 RR Race's cooling system is optimized for high-revving performance with forced liquid circulation via an impeller-driven pump, making coolant quality and volume critical to engine health*.
  • Beta factory guidance does not include a separate air bleeder screw from 2020 onwards; air is purged by careful topping and rocking of the bike during refill*.
  • Only use recommended, pre-mixed coolant for aluminum alloy radiators—mixing types can cause corrosion or poor heat transfer.
  • Never ingest coolant and avoid prolonged skin contact; Beta documentation warns coolant is toxic and hazardous if swallowed or exposed to open wounds*.
  • A regular coolant change annually, or as part of your racing maintenance schedule, is highly recommended.

FAQs and Troubleshooting

  • Air Bubbles? If coolant level drops after cooling, top off. Persistent bubbling or loss may indicate a leak or improper installation.
  • Coolant Expansion Bottle Some models use a reservoir as an expansion tank–check and fill accordingly.

Maintaining your 2021 Beta 125 RR Race with routine coolant changes preserves peak cooling performance, protecting your investment during the toughest rides and races.

* Reference: 2020-2021 Beta RR 2-Stroke Owner's Manual and Beta service documentation.

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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.