How to Change the Oil in a 2021 Suzuki DR-Z400SM

Shop parts for a 2021 Suzuki DR-Z400SM Dirt Bike.

Maintaining your 2021 Suzuki DR-Z400SM is essential to maximizing its performance – and longevity. One of the most crucial routine tasks is an oil change. Below, MotoSport.com provides a comprehensive, proprietary step-by-step guide that covers the required tools, parts, and specific tips for this model year.

Tools & Parts Needed

  • Ratchet
  • 8mm, 12mm, and 17mm sockets
  • Torque wrench
  • Drain pan
  • Rags and gloves
  • Funnel
  • New oil filter (Hiflofiltro HF139 recommended)
  • 2 quarts SAE 10W-40 motorcycle oil (example: Motul 5100 10W-40)
  • New crush washers for drain bolts (optional, but recommended)

Preparation

  • Run the bike for 3-5 minutes so the oil warms up and flows out more easily.
  • Turn off the engine and let it cool slightly to avoid burns.
  • Ensure your work area is clean and the bike is on a level stand.

Step-by-Step Oil Change Instructions

  • Remove the oil filler cap/dipstick.

    This is located at the top of the frame. Removing the cap allows the system to vent and drains the oil faster.
    Tip: Place a rag around the area to catch any drips.

  • Drain the crankcase oil.

    Position your drain pan under the engine. Use a 17mm socket to remove the main drain bolt and its washer under the crankcase. Allow oil to fully drain.
    Inspect the washer–Replace it if damaged or worn for proper sealing.

  • Reinstall and torque the crankcase drain bolt.

    Reinstall the bolt with its washer, tightening to 15 ft-lbs using a torque wrench for a snug, leak-proof fit.
    Overtightening risks stripping the soft aluminum threads.

  • Drain the lower frame oil.

    Move the drain pan to the bottom of the lower frame and use a 12mm socket to remove the frame drain bolt and washer. Let oil drain out completely.
    2021 DR-Z400SM specific callout: This dual oil drain system (crankcase and frame) is unique to the DR-Z's dry-sump lubrication. Always drain both points for a complete change.
    Replace the washer if necessary and torque bolt to spec (check owner's manual for exact value, typically similar to crankcase bolt).

  • Remove and replace the oil filter.

    The filter is mounted at the right side of the engine behind a round cover held by 8mm bolts. Remove these bolts, take off the cap, and pull out the old filter. Inspect the rubber O-ring on the cover—replace it if cracked or flattened.
    Oil and install a new filter, then reinstall the cover, tightening the bolts evenly and snugly (do not over-tighten).

  • Optional: Check the frame oil screen.

    There's a mesh filter/screen at the base of the frame where oil enters. This is rarely clogged, but you may remove and clean it as part of a thorough service, especially if the bike is new or has ever run on contaminated oil.

  • Add new oil.

    Place a funnel in the oil fill port at the top of the frame.
    Oil capacity:

    • 1.8 liters (with filter change)
    • 1.7 liters (oil only, no filter change)
    Pour in the correct amount of 10W-40 motorcycle oil (specifically meeting SF or SG standards). Reinstall the filler cap/dipstick.

  • Start the motorcycle and circulate oil.

    Start the engine and let it idle for 3-5 minutes. Check for leaks at the drain bolts and filter cover. Shut off the motorcycle, let it settle for a few minutes.

  • Check oil level.

    Remove the dipstick, wipe clean, reinsert (do not screw in), and check level. Add oil if below the upper mark; do not overfill.

  • Inspect for leaks and clean up.

    Look over all bolts and the filter area for oil drips. Reinstall the skid plate if removed. Dispose of old oil and the filter at a hazardous waste facility.

  • Test ride and re-check.

    Take a short ride, park on a level surface, and re-check for leaks and oil level.

Special Model-Specific Notes

  • 2021 DR-Z400SM:
    • This model uses a dry-sump system—always drain both the crankcase and the frame. Missing this step can leave old, dirty oil mixed with the fresh fill.
    • Check the torque on all drain and filter cover bolts as overtightening can damage the aluminum threads.
    • Suzuki recommends oil changes every 3,500 miles or sooner with heavy use, and always after the first 600 miles on a new bike.
    • Use only oils that meet SF or SG specification for proper clutch operation.

Conclusion

Changing the oil in your 2021 Suzuki DR-Z400SM is straightforward and essential for maintaining a healthy engine. By following MotoSport.com's precise steps and tips, you'll ensure your dirt bike performs at its best with minimal risk of leaks or damage. Always refer to your OEM service manual for torque specs and technical details specific to your bike.

This proprietary content is presented by MotoSport.com. For more how-to guides and all your motorcycle parts needs, trust MotoSport.com.

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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.