How to Change the Oil in a 2021 KTM 350SXF

Shop parts for a 2021 KTM 350SXF Dirt Bike.

Routine oil changes are crucial for maintaining your 2021 KTM 350SXF’s performance and longevity. This guide will walk you through the process, highlighting the tools you’ll need, the proper technique, and important call-outs unique to this model.

Tools and Supplies Needed

  • 13mm socket (or the correct size for your drain bolt and oil filter cover bolts)
  • Ratchet wrench
  • Torque wrench
  • Drain pan
  • Clean rags
  • Oil filter (KTM OEM or high-quality aftermarket replacement)
  • Fresh oil (the 2021 KTM 350SXF requires approximately 1.1 liters of 10W-50 four-stroke motorcycle oil, Motorex is recommended by KTM)
  • Funnel
  • Gloves (recommended for cleanliness)
  • Parts cleaner or brake cleaner (optional, for cleaning parts and the bike)

Preparation

  • Start with the engine warm but not hot–the oil drains more completely but won’t burn you.
  • Place your bike upright on a stand for easy access and to allow oil to drain evenly.
  • Clean the area around the drain and fill bolts to prevent dirt from entering the engine.

Step-by-Step Oil Change Process

  1. Drain the Oil
    • Locate the oil drain bolt under the engine. Position your drain pan directly beneath it.
    • Using your socket and ratchet, remove the drain bolt. Allow the oil to fully drain out.
    • Inspect the copper crush washer on the drain bolt for damage or flattening; replace it if needed to avoid leaks.
  2. Remove and Inspect the Oil Filter
    • On the right side of the engine, locate the oil filter cover. Remove the bolts using your socket.
    • Gently pull out the oil filter. Be careful of any residual oil that may spill out.
    • Check the old filter for excessive metal shavings or unusual debris, a sign of internal engine wear.
    • If your model also has oil screens (check your owner’s manual), remove, clean, and inspect them before reinstalling.
    • Clean the filter cover and replace the O-ring if it’s brittle or damaged.
  3. Install the New Oil Filter
    • Insert the new filter, making sure it seats fully and correctly (open side in, if noted in your manual).
    • Replace and hand-tighten the filter cover bolts. Use your torque wrench to tighten to factory spec (generally around 7.4 Nm; always confirm in your owner’s manual and don’t overtighten).
  4. Replace the Drain Bolt
    • Reinstall the cleaned drain bolt with the (new or cleaned) washer. Start threading by hand to avoid cross-threading.
    • Tighten with a torque wrench to manufacturer spec (don’t overtighten; over-torquing can damage the threads).
  5. Refill with New Oil
    • Remove the oil fill cap (on the right side of the engine). Set your funnel in place to avoid spills.
    • Pour in 1.1 liters of oil (KTM recommends Motorex 10W-50, but always use quality motorcycle-specific oil).
    • Replace the fill cap and wipe away any spills.
  6. Check the Oil Level
    • Let the bike sit for a minute to allow oil to settle. Check the oil level through the sight glass, which is located behind the rear brake lever.
    • If the oil isn’t visible or isn’t between the “min” and “max” marks, add a little at a time and re-check, but do not overfill. The correct level should be between the middle and top of the round marking in the sight glass when the bike is upright, with the rear brake pedal pressed down to view better as needed.
  7. Final Start-up and Inspection
    • Start the engine and let it idle for a minute. Watch for the oil pressure light to turn off (if equipped), and listen for any unusual noises.
    • Check for leaks at the drain bolt and around the filter cover.
    • Turn the engine off, let it rest for a couple of minutes, and check the oil level one more time, topping off if needed.

Model-Specific Call-Outs for the 2021 KTM 350SXF

  • Oil Quantity: 1.1 liters is standard, but always confirm in your owner’s manual as running low or overfilling can damage the engine.
  • Filter and Screen Maintenance: The KTM 350SXF uses both an oil filter and two oil screens. Clean both screens (locations are noted in your manual) at every oil change for optimum oil flow and engine safety.
  • Sight Glass Location: The oil level sight glass is somewhat hidden behind the brake lever—push the lever down for a clear view while checking oil level.
  • Drain Bolt Torque: The drain and filter cover bolts require very little torque (about 7.4 Nm). Over-torquing is a common cause of damage.
  • Change Interval: Many owners of the 2021 KTM 350SXF change their oil every 5 engine hours. If you race or ride in very dirty or muddy conditions, consider changing oil after every ride for maximum engine life.
  • Oil Type: Use only four-stroke motorcycle oil as specified by KTM, preferably Motorex Cross Power 4T 10W-50 or a similar high-performance oil.

Helpful Tips

  • Keep a maintenance log—note your engine hours at every oil change for easy tracking.
  • Dispose of old oil and filters responsibly—auto parts stores and many MotoSport.com partners offer recycling programs.
  • Always double-check all bolts for correct tightness after your first ride post-service.

Changing the oil on your 2021 KTM 350SXF is straightforward and essential for peak performance. Always use the recommended oil and genuine or high-quality replacement parts for the best results.

Related Shopping Categories

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Shop Tools for a 2021 KTM 350SXF Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 2021 KTM 350SXF 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.