How to Change the Oil in a 2007 Husqvarna WR125

Shop parts for a 2007 Husqvarna WR125 Dirt Bike.

This step-by-step guide is proprietary content for MotoSport.com, detailing exactly how to change the oil in a 2007 Husqvarna WR125 dirt bike. If you ride one of these legendary 2-strokes, regular oil changes keep your gearbox running smoothly and minimize wear — here's how to get it done right.

Tools and Materials Needed

  • Socket wrench (correct size for drain bolt, usually 13mm or 14mm)
  • Catch pan or oil drain container
  • Funnel
  • Replacement oil (see recommendations below)
  • Shop towels/rags
  • Gloves (optional, to keep hands clean)
  • New drain plug gasket or washer (recommended if the old one is worn)
  • Flathead screwdriver (if needed for plastic covers)

Recommended Oil for the 2007 Husqvarna WR125

  • Oil type: Use a high-quality, fully synthetic 2-stroke light gearbox oil, 75W recommended by many experienced WR125 owners. Alternatives include 10W-40 or, if specified in your manual, even a 4T 5W-40. Avoid automatic transmission fluid (ATF) as it can cause excessive clutch slip or milky oil due to water ingress.
    Tip: Castrol MTX or Putoline are popular, but always confirm with your latest manual and local climate.
  • Oil volume: Check the capacity in your owner's manual (typically around 700–800ml for the WR125, but always double-check as overfilling or underfilling can damage the transmission).

Step-By-Step Oil Change Instructions

  • 1. Warm up the engine
    Start and idle the bike for 2-3 minutes; this allows the oil to warm up and flow more easily, taking contaminated particles with it.
  • 2. Secure the bike
    Place your WR125 on a stand or level surface to keep it upright.
  • 3. Prepare the area
    Lay rags or cardboard under the engine to catch spills. Put on gloves for protection.
  • 4. Locate and loosen the drain bolt
    The oil drain plug is on the underside of the engine's left (shift) side. Use your socket wrench to slowly loosen the plug. Have the catch pan ready beneath.
    Specific 2007 WR125 call-out: Be sure the old crush washer comes off with the plug; if not, remove it to install a fresh one later.
  • 5. Drain the oil
    Remove the drain plug fully and let the oil flow into the drain pan. Allow several minutes for all oil to leave the gearbox. Tilt the bike gently side to side to help evacuate any trapped oil, but avoid excessive lean.
  • 6. Inspect and clean
    Clean the drain plug. Check for metal shavings on the magnetic tip—a small amount is normal, but lots or large chips could signal internal wear.
    Wipe the area around the drain hole with a rag to remove residual oil and debris.
  • 7. Replace the drain plug and gasket
    Fit a new crush washer, then reinstall the drain plug by hand to avoid cross-threading. Tighten with your socket wrench securely—do not over-tighten (refer to your manual for torque spec if available).
  • 8. Add fresh oil
    Unscrew the gearbox filler cap (usually located on the upper left side of the engine). Insert a funnel and pour in the recommended amount of new oil.
  • 9. Check oil level
    Some WR125s use a check bolt (sight screw) located on the right engine case—remove it briefly to see if oil drips out (level correct) or not (add more). Otherwise, use the sight glass if equipped.
    Specific 2007 WR125 note: Overfilling can cause clutch drag and leaks; underfilling can accelerate wear. Always measure carefully.
  • 10. Clean up and test
    Wipe any drips and ensure the drain and fill caps are tight. Dispose of old oil responsibly at a recycling or auto parts center.
  • 11. Run and recheck
    Start the engine for a couple of minutes, then shut off and recheck for leaks around the drain plug and the fill cap. After a short ride, check the oil level again and top up if necessary.

2007 Husqvarna WR125 Owner-Specific Call-Outs

  • Gasket condition: Husqvarna recommends replacing the drain plug gasket with every oil change to avoid leaks, especially on older engines with flattened or worn washers.
  • Oil selection: The wrong oil viscosity or using automotive transmission fluid can cause the oil to turn milky due to condensation or water ingress. If your oil appears consistently milky, check for possible water seal issues and consider slightly thicker synthetic oil as per rider feedback.
  • Torque specifications: Always refer to your exact workshop manual for correct drain plug torque—overtightening is a common cause of stripped threads on the aluminum engine cases.

Final Tips

  • Always change the oil after deep water crossings or extended wet riding, as moisture can enter the gearbox on dirt bikes like the WR125.
  • Use high-quality oils to prolong gearbox and clutch life; avoid mixing different types or brands if possible.
  • Check for leaks after your first post-change ride, and inspect old oil for debris at every change.

With these steps, your 2007 Husqvarna WR125 will stay in top condition, shifting smoothly and riding reliably on every trail. Trust MotoSport.com for more proprietary how-tos and all your dirt bike parts and maintenance supplies.

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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.