How to Change the Coolant in a 1993 Suzuki DR350S

Shop parts for a 1993 Suzuki DR350S Dirt Bike.

Changing the coolant on a 1993 Suzuki DR350S is a crucial part of regular maintenance, protecting the engine from overheating and preventing internal corrosion. The DR350S is an air/oil-cooled model that features both a waterless cooling system for the cylinder and a compact design, so it is especially important to maintain the proper coolant level to ensure optimal performance and longevity. Use only recommended coolant types–avoid hard water or automotive coolant containing silicates as they may damage your bike.

Required Tools & Materials

  • Drain pan
  • Rags
  • Small funnel
  • New drain bolt washer (copper or aluminum is best)
  • Coolant (motorcycle-specific, premixed or concentrate with distilled water)
  • Gloves and safety glasses

Step-by-Step Guide

1. Prepare the DR350S

  • Ensure the engine is completely cool before you begin.
  • Secure the bike on a stand for easy access and stability.

2. Locate Draining Components

  • Identify the coolant drain bolt on the base of the cylinder or water pump housing (lowest point on the system).
  • Remove any panels or guards if necessary for access.

3. Drain the Old Coolant

  • Keep the radiator cap on to minimize flow until the drain bolt is out.
  • Place a drain pan beneath the drain bolt and remove the bolt (watch for the sealing washer).
  • After the bolt is out, slowly remove the radiator cap or fill plug. Coolant will begin to flow freely.
  • When drained, remove the coolant reservoir if equipped and empty any remaining coolant. Clean the reservoir as needed.

4. Optional: System Flush

  • If flushing, reinstall the drain plug and pour in a 50/50 mix of white vinegar and distilled water.
  • Run the engine briefly until warm (not hot). Let it cool, then drain. Rinse at least once with distilled water and drain again.

5. Reassemble and Inspect

  • Install a new drain bolt washer to prevent leaks.
  • Tighten the drain bolt securely but do not overtighten–you could damage the threads.
  • Reinstall the coolant reservoir.

6. Refill with Fresh Coolant

  • Pour the proper coolant slowly into the radiator or fill port using a funnel, filling to the brim. Avoid creating bubbles.
  • Top off the expansion tank (if present) to the upper fill line.
  • Install the caps securely.

7. Bleed and Check System

  • Start the engine and let it idle for 2-3 minutes. Occasionally blip the throttle to encourage air bubble removal.
  • Stop the engine, allow the bike to cool, then recheck coolant level in both the radiator and tank. Top up as needed.
  • If the coolant level drops after a short ride, recheck and top off again. Monitor levels over your next several rides.

DR350S Model-Specific Maintenance Tips

  • This model uses a high-mounted oil cooler and features a relatively simple cooling system, but correct sealing is essential. Always use a new washer on the drain bolt.
  • Avoid mixing different types of coolant–stick to one that is approved for motorcycle use and safe for aluminum engines.
  • Inspect hoses and clamps for signs of aging or leaks. Replace any cracked or bulging hoses.

Coolant Disposal & Environmental Safety

  • Never pour used coolant down the drain. Seal in a container and take to a hazardous waste facility.

Proper coolant maintenance will help keep your 1993 Suzuki DR350S running smoothly for years, whether you're ripping through trails or commuting. Always consult your owner's manual for any year-specific procedures or coolant recommendations.

Related Shopping Categories

Shop Radiators for a 1993 Suzuki DR350S Dirt Bike.

Shop Coolant for a 1993 Suzuki DR350S Dirt Bike.

Shop Temperature Sensors for a 1993 Suzuki DR350S Dirt Bike.

Shop Tools for a 1993 Suzuki DR350S Dirt Bike.

Shop Radiator Hoses for a 1993 Suzuki DR350S 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.