How to Change the Coolant in a 1995 Suzuki RM250

Shop parts for a 1995 Suzuki RM250 Dirt Bike.

The 1995 Suzuki RM250 remains an iconic two-stroke dirt bike with a liquid-cooled engine, making proper cooling system maintenance essential for performance and longevity. Changing the coolant is a straightforward job most owners can tackle with common hand tools. Below is a step-by-step guide tailored specifically for your RM250, plus technical notes all owners should know about this MMY model.

Tools and Supplies Needed

  • Fresh coolant (choose a quality motorcycle-specific formula)
  • Socket set and wrenches
  • Drain pan
  • Phillips screwdriver
  • Funnel
  • Shop rags and gloves

Preparation

  • Ensure the bike is fully cool before starting. Never open the radiator cap on a hot engine – scalding coolant under pressure can cause severe burns.
  • Set the RM250 upright on a stand for stable access to work areas.

Draining the Old Coolant

  • Remove the seat and front shrouds for easier access to the radiator caps and hoses.
  • Locate the radiator cap on top of the left radiator and slowly loosen it to relieve residual pressure, then remove it fully.
  • Position a drain pan under the engine area. Locate the engine's coolant drain bolt on the water pump cover, typically the lowest bolt with a copper washer.
  • Using a wrench, loosen and remove the drain bolt. Allow the coolant to drain completely.
  • You can also remove the lower radiator hose (using your pliers/screwdriver) to aid draining and flushing. Pro tip: Leave the radiator cap off to allow full drainage.

Flushing (Recommended)

  • If switching coolant types or after extensive riding, flush the system with distilled water. Reinstall the drain bolt, fill with water, and circulate briefly or as directed in your service manual.
  • Drain again, and repeat if the fluid is still contaminated. Do not use tap water, as it can introduce harmful minerals.

Refilling with New Coolant

  • Reinstall and tighten the drain bolt with its washer. Avoid overtightening, as these aluminum threads strip easily. Typical spec: 11 N·m (8.0 lbf-ft).
  • Using a funnel, fill the radiator with fresh coolant up to the bottom of the filler neck. The RM250's system generally holds just under 1 liter.
  • Check for a bleeder bolt on or near the radiator. If present, loosen it slightly as you fill to allow trapped air to escape. Once coolant seeps from the bolt without bubbles, re-tighten to factory torque specification.
  • Replace the radiator cap securely.

Bleeding Air and Checking Level

  • Start the bike and let it idle for several minutes with the radiator cap on. Watch for air pockets escaping in the overflow tank, and gently rock the bike side-to-side to dislodge trapped air.
  • Let the engine cool and recheck coolant level, topping off as needed.

Disposal and Final Check

  • Carefully dispose of old coolant as it is toxic to humans, pets, and the environment.
  • Double-check for leaks at the drain bolt and hose connections after your first ride.

Special RM250 Notes

  • Unlike four-strokes, your 1995 RM250 uses a simpler water jacket cooling design. Pay attention to the condition of hoses & seals, as aging two-strokes can develop leaks from dried rubber.
  • Inspect radiator fins for mud or debris, which can restrict airflow and cause overheating – this is especially common on older motocross bikes.
  • If you ride muddy or tight tracks often, clean both sides of the radiator and consider adding protective rad guards.
  • Frequent coolant checks are recommended for competitive or high-rpm use.

Regular coolant changes extend the life of your RM250 and keep you on the throttle, not stuck on the track. Tackle this easy maintenance task yourself – it is one of the best ways to protect your engine investment.

Related Shopping Categories

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Shop Radiator Hoses for a 1995 Suzuki RM250 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.