How to Change the Oil in a 1990 Suzuki DR250S

Shop Parts for a 1990 Suzuki DR250S Dirt Bike.

Keeping your 1990 Suzuki DR250S running strong requires routine oil changes. In this guide, MotoSport.com explains everything you need to know to change the oil yourself, identifies all the tools and parts required, and highlights important model-specific tips to help you achieve a professional-quality job in your own garage.

Tools & Supplies Needed

  • Socket set and ratchet (for drain plug and oil filter cover bolts)
  • Oil drain pan
  • Funnel
  • Clean rags
  • New oil filter
  • Replacement O-rings (recommended for filter cover and drain plug if worn)
  • Torque wrench (optional, for precise reinstallation)
  • 1.9 liters of quality motorcycle oil (per Suzuki spec; semi-synthetic or full synthetic, 10W-40 is a common choice) .

Step-by-Step Instructions

  • Warm Up the Engine
    Run your DR250S for a few minutes to thin out the oil, allowing for a more complete drain. Park the bike on a level surface and turn it off.
  • Remove Skid Plate (If Installed)
    The 1990 DR250S often has a skid or bash plate. Removing it makes it easier to access the engine and drain plugs but is not mandatory. If you want to do a thorough job, taking it off is recommended.
  • Drain Frame Oil (Dry Sump System)
    Locate the oil drain bolt on the lower frame tube—this is critical for dry sump Suzuki models like the DR250S. Position your drain pan under the frame tube and remove the bolt. Allow oil to drain completely.
  • Drain Engine Crankcase
    Find the sump plug underneath the engine. Remove this plug and let the oil drain entirely into your pan. Wait until it slows to a drip.
  • Remove and Replace the Oil Filter
    The oil filter is housed behind a small round cover on the right side of the engine. Loosen the bolts (note their different lengths/positions for reinstallation), remove the cover, and take out the old filter. Replace the filter with a new one. Inspect O-rings and replace if damaged or flattened to avoid leaks.
  • Inspect and Clean Oil Strainer
    The DR250S uses a mesh oil strainer in the frame tank. Remove and inspect it for debris, then clean with solvent if necessary and reinstall.
  • Replace Drain Plugs/Oil Filter Cover
    Wipe the drain plugs, reinstall with new crush washers if needed, and tighten securely. Replace the skid plate if removed.
  • Add New Oil
    Pour about 1.9 liters of new oil into the frame filler cap using a funnel. Suzuki recommends measuring carefully—do not overfill, as the dry sump design separates oil storage from the crankcase.
  • Start Engine & Check for Leaks
    Start the motorcycle, let it idle for 2–3 minutes, then shut it off. Wait a few moments, check for leaks at the drain plugs and filter cover.
  • Check Oil Level
    With the bike on level ground, check the oil level using the dipstick (in the frame neck). Add more oil if necessary to bring it up to the correct level.
  • Dispose of Old Oil Properly
    Take the used oil to a recycling center or auto parts store—never pour it down a drain or on the ground.

Special Model-Specific Tips for 1990 Suzuki DR250S Owners

  • The dry sump design means oil is stored in the frame, not the engine case. Always drain both the frame tank and crankcase for a proper oil change, and clean the mesh oil strainer in the frame.
  • Oil volume is 1.9 liters with filter change. Overfilling can cause engine damage—measure carefully.
  • For the first oil change after purchase or long storage, watch for milky or contaminated oil (could indicate past water or fuel contamination). If so, refill with fresh oil, run briefly, and change again to flush out residue.
  • Always replace the large O-ring on the oil filter cover if it’s hard, cracked, or flattened to prevent leaks.

Conclusion

Routine oil changes are a critical part of caring for your 1990 Suzuki DR250S. By following the correct procedure and checking all the required service points, you help extend engine life and keep your bike ready for the trail. With the proper tools, attention to detail, and this MotoSport.com guide, you can handle this essential maintenance job confidently in your own garage.

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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.