How to Change the Coolant in a 2009 Yamaha WR250R (Dual Sport): A Complete MotoSport Guide

Shop parts for a 2009 Yamaha WR250R Dirt Bike.

Changing the coolant on your 2009 Yamaha WR250R dual sport is an essential maintenance task – it keeps your engine running cool on and off road. Here—s a step-by-step guide from MotoSport, customized for the WR250R, and including pro tips unique to this model.

Tools & Supplies Needed

  • Fresh motorcycle-specific coolant (not car coolant)
  • Distilled water (for flushing)
  • Socket set (specifically 8mm for panels, and 12mm for drain plug)
  • Phillips screwdriver
  • Funnel
  • Drain pan
  • Shop rags
  • Allen keys
  • Torque wrench

Preparation – Important Model Notice

The WR250R's coolant reservoir is tucked behind the left panel and is notoriously tight to access. Setting your workspace up in advance and having patience when removing the reservoir will go a long way. Always use motorcycle coolant—automotive versions can damage the WR250R&apost;s water pump seals due to differing additives.

Step 1: Remove Panels and Seat

  • Use the 8mm socket and Phillips screwdriver to remove the side panels and seat for clear access to the radiator and coolant reservoir.

Step 2: Drain the Old Coolant

  • Place your drain pan under the water pump area on the lower right of the engine (look for the coolant drain bolt).
  • Remove the radiator cap (engine cool to touch).
  • Loosen the coolant drain bolt and allow all coolant to drain fully.
  • Remove the small bolt on the water pump cover to act as a vent, letting the coolant flow out more completely.

Step 3: Flush the Cooling System

  • Briefly reinstall the drain bolts and fill the system with distilled water only.
  • Start the bike for 30–60 seconds, let it circulate, then turn off and drain again.
  • Repeat if coolant appears contaminated—dirt bikes like the WR250R often accumulate grit with age.

Step 4: Reservoir Removal and Drain (Special Model Note)

  • On the WR250R, the reservoir bottle can be tricky to wiggle out. Carefully disconnect the vent tube and mounting screws.
  • Remove the reservoir and rinse with distilled water, ensuring all old coolant and possible debris are washed out.

Step 5: Refit Draining Bolts and Torque

  • Replace and hand-thread the drain bolts, then torque to manufacturer specifications. Inspect gaskets for wear.

Step 6: Refill With Fresh Coolant

  • Pour new, pre-mixed motorcycle coolant into the radiator until it reaches the filler neck.
  • Fill the reservoir to the "Full" mark (be sure to reconnect its hoses).

Step 7: Bleeding Air from the System

  • Run the engine with the radiator cap off in an upright position and watch for air bubbles escaping.
  • Top off as needed until the bubbles subside, then fit the radiator cap.

Step 8: Reassemble Panels and Seat

  • Reverse the disassembly steps for side panels and the seat.

Step 9: Final Check

  • Inspect for leaks at all bolt locations and hose connections. Check the reservoir level after the first ride and top off if necessary.

WR250R Coolant System Tips & Reminders

  • Only use coolant specified for motorcycles; the WR250R's water pump is sensitive to certain additives.
  • Check for signs of oil in the coolant – a rare issue, but important for diagnostics (could indicate a gasket leak).
  • Be patient when removing and refitting the coolant reservoir – access is limited, which is normal for this year/model.
  • Always dispose of used coolant safely – never dump it outdoors.

Performing this service as recommended in your maintenance schedule will keep your WR250R performing at its best on the trail, the street, or wherever your adventure leads.

Related Shopping Categories

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Shop Radiator Hoses for a 2009 Yamaha WR250R 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.