How to Change the Oil in a 2018 GAS GAS TXT GP 250

Shop parts for a 2018 GAS GAS TXT GP 250 Dirt Bike.

Changing the oil in your 2018 GAS GAS TXT GP 250 is critical maintenance that boosts performance and ensures engine longevity. Follow this MotoSport.com proprietary guide to complete the job like a pro. This guide covers the essential tools needed, a detailed step-by-step process, and unique model-specific tips for your trial bike.

Tools & Materials Needed

  • Socket set and appropriate spanners (check the drain bolt size, typically 13mm or 17mm for TXT models)
  • Oil drain pan
  • Funnel (paper or plastic)
  • Contact cleaner (optional, for cleaning up spills)
  • Clean shop rags
  • New crush washer for drain bolt (recommended)
  • Measuring cup or graduated container
  • Recommended gear oil (common choice: GRO Gear Oil or high-quality 75W light gear oil)
  • Torque wrench (optional but ideal for precise tightening)
  • Gloves (optional, for hand protection)

Recommended Oil Specification

  • Use a specialized gear oil formulated for trials bikes. Many experienced riders prefer GRO Gear Oil, but a light 75W gear oil meeting GAS GAS requirements is suitable.

Oil Quantity

  • The TXT GP 250 oil capacity is typically between 350-450 ml. Always check your owner's manual or current fill amount; more is not better.

Step-by-Step Oil Change Process

  1. Warm Up the Engine
    • Briefly run your TXT GP 250 for 1-2 minutes. This warms the oil, helping it drain more thoroughly. Do not let the bike become hot.
  2. Position the Bike Securely
    • Use a flat lift stand to keep the bike level and prevent it from tipping. This is especially important for a lightweight trials bike.
  3. Remove the Filler Cap
    • Unscrew the gear oil filler cap on the right side of the crankcase. This allows air to move freely and speeds up draining.
  4. Clean Around the Drain Bolt
    • Wipe down the area around the oil drain bolt with a rag to prevent debris from entering the engine.
  5. Drain the Gear Oil
    • Place a drain pan under the engine.
    • Use the correct-sized spanner (commonly 13mm or 17mm) to unscrew the oil drain bolt located underneath the gear box.
    • Let the oil fully drain. Allow a few extra minutes for the last drops.
  6. Inspect and Replace Washer
    • Check the crush washer on the drain bolt. Replace with a new washer to prevent leaks.
    • Inspect the condition of the old oil for metal or milky appearance (could indicate water ingress).
  7. Reinstall the Drain Bolt
    • Screw in the drain bolt by hand first, then tighten with your spanner or torque wrench to specified torque (do not overtighten–this is a common mistake and can damage the crankcase threads).
    • Typical torque spec is 10–12 Nm; check your manual.
  8. Add Fresh Oil
    • Using a funnel, pour in the specified volume of fresh gear oil (350–450 ml depending on manual and your riding style).
    • Pour slowly to avoid overflow and allow oil to settle.
    • Replace the filler cap securely.
  9. Check Oil Level
    • Start the bike and let it idle for 30 seconds, then shut off and allow oil to settle for a minute.
    • Check the sight glass or dipstick. If the level is low, add a bit more oil. Never overfill, as this can cause clutch drag or gearbox issues.
  10. Inspect for Leaks and Clean Up
    • Inspect the drain bolt and filler cap for any oil seepage. Wipe down excess oil from the engine with a clean rag and contact cleaner.
  11. Dispose of Old Oil Responsibly
    • Pour old oil into a sealed container and take it to your nearest recycling center or auto parts shop.

Model-Specific Call-outs for the 2018 GAS GAS TXT GP 250

  • Drain Bolt Location: On the TXT GP, the gear oil drain bolt sits underneath the right side of the motor. Always reference your frame number or consult your manual for confirmation if unsure.
  • Filler Cap: The filler cap is right above the clutch case, easily accessible without removing the tank or plastics on trials bikes.
  • Do Not Over-Tighten: It is very common to see stripped drain threads on TXT models. Always use a torque wrench or be cautious—snug, not tight, is the rule here. Stripping is a costly mistake.
  • Oil Type: Avoid using standard motor oil. Trials-specific light gear oil improves clutch performance and shifting feel.
  • No Oil Filter: Trials models like the TXT GP 250 do not have an oil filter—only regular oil changes flush contaminants.
  • Oil Inspection Window: Some models include a sight glass—check after running the engine and settling. If overfilled, drain a small amount.

Pro Tips for Best Results

  • Change oil every 10–15 hours of riding or after particularly wet/muddy rides to avoid clutch and gear issues.
  • Always keep a few spare crush washers in your toolbox for future changes.
  • If you ride in harsh conditions, inspect clutch plates and gearbox for contamination during oil changes.
  • Keep a maintenance log; knowing when you last changed oil helps resale value and performance tracking.

By following this MotoSport.com guide, you'll ensure smooth shifting, robust clutch action, and a reliable engine life for your 2018 GAS GAS TXT GP 250. Routine maintenance is the key to winning rides—make oil changes a regular habit.

Related Shopping Categories

Shop Motor Oil for a 2018 GAS GAS TXT GP 250 Dirt Bike.

Shop Oil Filters for a 2018 GAS GAS TXT GP 250 Dirt Bike.

Shop Oil Drain Pans for a 2018 GAS GAS TXT GP 250 Dirt Bike.

Shop Tools for a 2018 GAS GAS TXT GP 250 Dirt Bike.

Shop Oil Fillers and Drain Plugs for a 2018 GAS GAS TXT GP 250 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.