How to Change the Oil in a 2009 KTM 85SX

Shop parts for a 2009 KTM 85SX Dirt Bike.

Changing the oil in your 2009 KTM 85SX is a must-do maintenance task that keeps your bike shifting smoothly and extends engine life. This guide, brought to you by MotoSport.com, is designed to provide everything you need to know — from tools required, to step-by-step instructions, and specific tips just for this make and model.

Tools and Supplies Needed

  • 8mm and 13mm sockets or wrenches (for drain plug and oil fill cap)
  • T-handle wrench or ratchet
  • Torque wrench (for re-tightening the drain bolt)
  • New crush washer (for the drain plug)
  • Drain pan or oil catch container
  • Funnel
  • Clean rags
  • Full synthetic 2-stroke gear oil (Motorex or Amsoil recommended; capacity: 0.8 liters)
  • Nitrile gloves (recommended)

Before You Begin

  • Only use high-quality full synthetic oil, such as Motorex or Amsoil; cheap oils are not recommended and can shorten gearbox life.
  • Warming up the engine for a few minutes will help the oil flow out more completely, but be careful—the oil will be hot.
  • If your bike is muddy or dirty, clean around the drain plug and oil fill cap to prevent debris from falling into the engine.
  • The oil drain bolt is located directly beneath the brake lever on the underside of the engine case.
  • The oil fill cap is located on the right side, above the clutch cover; the oil check bolt is just below it for verifying oil level if desired.

Step-By-Step: Changing the Oil

  1. Prepare the Bike
    • Place your bike on a stable stand.
    • Ensure the engine is warm (not hot) for the best draining results.
    • Set your drain pan underneath the engine so it will catch the oil from the drain bolt.
  2. Remove the Oil Fill Cap
    • Use your wrench or by hand, loosen and remove the oil fill cap. This allows air in and helps the oil drain faster.
  3. Remove the Drain Bolt
    • Locate the large drain bolt under the brake lever.
    • Using the correct size socket (usually 13mm), loosen the bolt carefully and remove it by hand.
    • Be cautious not to drop the bolt into the catch pan as the oil drains. Allow all old oil to fully drain from the engine case.
  4. Inspect and Clean the Drain Bolt
    • Inspect the magnetic tip of the drain bolt. It may have metallic debris attached; a small amount is normal and indicates the gearbox is wearing in properly.
    • Wipe the bolt thoroughly with a rag.
    • Replace the crush washer with a new one to ensure a proper seal and prevent leaks.
  5. Reinstall the Drain Bolt
    • Thread the drain bolt by hand to avoid cross-threading.
    • Torque the bolt to the specified 20 Nm (14.8 ft-lb) using your torque wrench.
  6. Refill with Fresh Oil
    • Insert your funnel into the oil fill port.
    • Pour in 0.8 liters (800 ml) of recommended full synthetic gear oil (Motorex is KTM‘s top choice for this model). Do not overfill.
    • If you wish to check the oil level precisely, use the check bolt located just below the fill port.
  7. Replace the Oil Fill Cap
    • Reinstall the oil fill cap by hand and snug it down with pliers if necessary (per KTM‘s recommendation, but avoid overtightening).
  8. Dispose of the Old Oil Properly
    • Seal the used oil in a suitable container and bring it to a recycling or waste center; never dump it on the ground or in the trash.
  9. Run and Inspect
    • Start the bike briefly, let it idle, and check for leaks by inspecting the drain plug and fill cap area.
    • Check the gearbox oil level one more time and top up if necessary.

2009 KTM 85SX Model-Specific Callouts

  • Be aware that the 85SX uses full synthetic gear oil only; the use of cheaper or mineral oils can cause premature clutch and transmission wear.
  • Capacity is 0.8 liters–don‘t overfill, as this can cause increased internal pressure or leaks.
  • The magnetic drain plug is designed to collect small metal shavings, which is normal. Excessive debris may indicate a problem and should be inspected by a professional.
  • Always replace the crush washer each time you change the oil for best results and leak prevention.

Extra Tips for KTM 85SX Oil Changes

  • Change your oil every 5-10 hours of riding for best performance, more frequently if riding in harsh, muddy, or sandy conditions.
  • Keep a log of your oil changes to monitor your maintenance schedule and catch potential problems early.
  • Never mix biodegradable hydraulic clutch oil with mineral oils if servicing the clutch system; only use the specified KTM-approved clutch fluids.

Stay tuned to MotoSport.com for more model-specific tips and top-quality parts for your KTM 85SX.

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Shop Oil Fillers and Drain Plugs for a 2009 KTM 85SX 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.