How to Change the Coolant in a 2023 Suzuki RM85

Shop parts for a 2023 Suzuki RM85 Dirt Bike.

Routine maintenance is critical to the performance and longevity of your 2023 Suzuki RM85. One of the most crucial but overlooked tasks is changing the engine coolant. Coolant keeps your engine running at the ideal temperature, protects from corrosion, and maintains peak performance–and the RM85's high-revving 2-stroke engine depends on a well-maintained cooling system. Follow this proprietary MotoSport.com guide designed specifically for your 2023 RM85.

What You Need

  • Fresh coolant (suitable for aluminum radiators, typically ethylene glycol-based)
  • Distilled water (optional, for flushing)
  • Catching pan
  • Socket set (usually 8mm for water pump drain bolt)
  • Clean rags
  • Torque wrench (recommended)
  • Funnel
  • Gloves and safety glasses

Before You Begin

  • Let your RM85 cool completely before starting. Never open the radiator cap on a hot engine—pressure can cause scalding coolant to spray out.
  • Work in a well-ventilated area and place your bike on a stable stand.

Step 1: Remove the Radiator Cap

With the engine cool, locate and slowly remove the radiator cap to relieve any residual pressure. The radiator is found at the front left side of the bike.

Step 2: Locate the Water Pump Drain Bolt

The water pump drain bolt is typically a small bolt at the lowest point on the right-side engine cover. Position your drain pan beneath it.

Step 3: Drain the Old Coolant

  • Use the correct socket to loosen (but not fully remove) the water pump drain bolt.
  • Let the coolant drain completely into the pan. Tilting the bike slightly side to side can help remove more old fluid.
  • Remove the radiator cap fully if you haven't already, to allow air in and speed up the draining process.

Step 4: Optional System Flush

For thorough maintenance, pour distilled water into the radiator and repeat the drain step. Never use tap water–minerals can damage your system. Do this until the water runs clear. Be sure to drain fully after the final flush.

Step 5: Reinstall the Drain Bolt

  • Inspect the crush washer (if equipped) and replace if worn or damaged.
  • Hand-tighten the drain bolt, then use a torque wrench to tighten to the RM85 manufacturer's specification.

Step 6: Fill with New Coolant

  • Place a funnel into the radiator neck.
  • Slowly pour in the recommended coolant until it reaches the bottom of the filler neck.
  • Pause occasionally to let bubbles escape—this prevents air pockets.

Step 7: Bleed the System

The 2023 RM85 cooling system is simple but air can still get trapped. To help bleed:

  • Tilt the bike gently side to side with the cap off.
  • Tap radiator hoses to dislodge trapped bubbles.
  • Let it settle, then top off to the proper level.

Step 8: Reinstall the Radiator Cap

Once coolant is at the correct level and all bubbles have purged, carefully secure the cap.

Step 9: Start & Check

  • Start the RM85 and let it idle for several minutes.
  • Watch the temperature (via the feel of radiator hoses–should get warm, not hot) and check for leaks, especially at the drain bolt and lower hoses.
  • Shut off the bike and allow it to cool. Re-check the coolant level and top off if necessary.

Tips for 2023 RM85 Owners

  • The RM85's radiator is compact and vulnerable to race impacts. Inspect for bent fins or leaks whenever you change coolant.
  • This model has no separate overflow bottle–any excess coolant will vent directly. Never overfill.
  • Use only non-silicate, aluminum-safe coolants. Avoid low-grade or automotive anti-freeze to prevent internal corrosion.
  • Regularly replacing coolant—at least once a year or more frequently under hard riding—prevents overheating and maximizes the life of your top-end.

Maintaining your 2023 Suzuki RM85 cooling system with fresh, premium coolant is essential for race-day reliability. For all your parts and maintenance needs, rely on MotoSport–your trusted source for Suzuki RM85 parts and accessories.

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Shop Radiator Hoses for a 2023 Suzuki RM85 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.