How to Change the Oil in a 2006 GAS GAS EC125

Shop parts for a 2006 GAS GAS EC125 Dirt Bike.

Changing the oil in your 2006 GAS GAS EC125 is a crucial maintenance task that helps ensure long engine life and smooth operation. While the EC125 is a two-stroke, remember that two-strokes use transmission oil, not four-stroke motor oil (which lubricates both the engine and the transmission in four-stroke engines). The oil change process is fairly straightforward, and doing it yourself can save money and keep your dirt bike running its best.

Tools and Materials Needed

  • Socket wrench set (including the correct size for the oil drain bolt, typically 13mm or 17mm – confirm with your owner's manual)
  • Catch pan for old oil
  • Replacement transmission oil (high-quality 10W-40 or manufacturer's recommended oil – check your manual for capacity and specification)
  • Funnel
  • Clean rag or paper towels
  • New crush washer (recommended, especially if the old one is damaged)
  • Torque wrench (preferred for reinstalling drain bolt to spec)
  • Gloves (optional, but keeps your hands clean)

Oil Change Procedure for the 2006 GAS GAS EC125

  • Warm up the engine
    Start the bike and let it idle for 2–3 minutes. This thins the oil, helping it drain more completely. Shut off the engine and set the bike upright on a stand.
  • Locate the oil drain bolt
    On the EC125, the drain bolt is typically located at the very bottom of the transmission case (left side of the bike, lower section). Confirm its exact location in your service manual if needed.
  • Place the oil catch pan
    Position a catch pan directly under the drain bolt to collect the used oil.
  • Remove the oil filler plug
    The oil filler plug is on the engine case (top left side), usually marked or easily spotted. Removing it helps the oil drain smoothly by allowing air in. After removing, set aside in a clean area.
    Note: Aftermarket filler plugs (such as AS3 Performance) are available for the EC125, but the original works fine if undamaged.
  • Remove the drain bolt
    Use the wrench to unscrew the drain bolt. As the oil starts to flow, be careful – it may be hot. Allow all the old oil to drain out completely.
    Tip: Tilting the bike slightly upright or from side to side can help remove more old oil.
  • Inspect and clean the drain bolt
    Wipe the bolt clean and inspect the crush washer. Replace the washer if it is damaged or crushed. The washer helps prevent leaks.
  • Reinstall the drain bolt
    Thread the drain bolt back in by hand to avoid cross-threading, then tighten gently with a wrench. If you have a torque wrench, tighten to the specification listed in your bike's manual.
  • Add fresh transmission oil
    Place a funnel in the oil filler hole. Pour in the manufacturer's recommended amount and type of two-stroke transmission oil (typically 650–700 ml, but confirm in your EC125 manual).
    Do not overfill – overfilling can cause leaks and shifting issues.
  • Reinstall oil filler plug
    Thread the filler plug in by hand and gently snug it down using the appropriate tool.
  • Check for leaks
    Start the engine and allow it to idle for a couple of minutes. Inspect the drain bolt and filler plug for any signs of leaking oil.
  • Dispose of used oil responsibly
    Pour the old oil into a sealable container and take it to a recycling or hazardous waste facility.

Specific Call-Outs for the 2006 GAS GAS EC125

  • Two-stroke transmission oil: The EC125 requires gear/transmission oil, not engine oil. Always use two-stroke-specific transmission oil to ensure proper lubrication of the gearbox.
    Do not use four-stroke motor oil in the EC125's transmission.
  • Oil Capacity: Always check your owner's manual for the exact oil quantity as the EC125 may vary slightly by year and production run.
  • Oil Filler Plug: Aftermarket oil filler plugs are available for improved aesthetics or easier removal. Ensure compatibility before replacing the stock plug.
  • Crush Washer: It is best practice to replace the crush washer every oil change to prevent leaks. If unavailable, inspect carefully and reuse only if fully intact.
  • Oil Change Interval: For peak performance, change the oil every 10–15 hours of riding, or more frequently if riding in extreme conditions or racing.

Frequently Asked Questions

  • What oil is best for the EC125?
    Use a high-quality synthetic two-stroke transmission oil, 10W-40 or the type recommended in your service manual. Motorex, Motul, and similar brands are popular choices.
  • Can I change the oil more often?
    Absolutely. More frequent changes are beneficial for hard or wet riding conditions.
  • What about the oil filter?
    The EC125 does not have a replaceable oil filter; only the oil itself needs changing.

MotoSport.com Proprietary Advice

  • Always use the correct oil grade and change intervals as prescribed by GAS GAS to prevent unnecessary gearbox wear.
  • Keep notes of each oil change in a maintenance log for resale value and future troubleshooting.
  • Inspect used oil for debris (such as metal flakes) which may signal internal wear and need for further inspection.
  • Stock up on crush washers (available at MotoSport.com) to avoid last-minute surprises.

Regular transmission oil changes are essential for your 2006 GAS GAS EC125. With routine care and correct oil, your dirt bike will remain reliable for many rides to come.

Related Shopping Categories

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Shop Oil Drain Pans for a 2006 GAS GAS EC125 Dirt Bike.

Shop Tools for a 2006 GAS GAS EC125 Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 2006 GAS GAS EC125 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.