How to change the oil in a 2021 Kawasaki KLX140R L 19/16 Dirt Bike

How to Change the Oil in a 2021 Kawasaki KLX140R L 19/16

Shop parts for a 2021 Kawasaki KLX140R L Dirt Bike.

Changing the engine oil is vital for the reliability and performance of your 2021 Kawasaki KLX140R L. This step-by-step blog will guide you through the entire process, highlighting tools required, model-specific tips, and making sure your dirt bike is ready to ride. This article is proprietary content for MotoSport.com.

Tools and Supplies Needed

• Ratchet and extension
• 8mm socket (for oil filter cover bolts)
• 17mm socket (for drain plug)
• Torque wrench
• Drain pan
• Clean funnel
• Shop towels or rags
• New OEM oil filter (part no. 52010-1053)
• New drain plug crush washer/gasket (part no. 11061-0421)
• Recommended oil: 10W-40 4-stroke motorcycle engine oil (approx. 1.1L – 1.2 quarts)
• Gloves
• Brake cleaner (optional, for cleaning up spills)
• Newspaper or cardboard to catch drips

Step-by-Step Guide

• Warm up the Engine
  Start your KLX140R L and let it idle for 2–3 minutes to warm up the oil. This makes the oil flow out more easily and carries away contaminants.
  Tip—Do not run the engine for too long – you just want the oil warm, not hot.
  
• Remove the Dipstick
  Shut off the engine and place the bike upright on a center stand or level ground. Remove the oil dipstick/fill cap. This step helps the oil drain out more quickly by venting the crankcase.
  
• Drain the Old Oil
  Position the drain pan under the left side of the engine (directly below the drain plug). Use a 17mm socket and ratchet to remove the drain bolt and the old crush washer. Be careful – the oil can be hot! Let the oil drain completely.
  KLX140R L Note—The drain plug is on the lower left side of the crankcase.
  
• Remove and Replace the Oil Filter
  While the oil finishes draining, locate the oil filter cover (held by three 8mm bolts). Place newspaper or rags underneath to catch drips. Remove the bolts and the cover. The oil filter may stick to the cover or stay in the cavity – either is normal. Remove the old filter and O-ring.
  Inspect the O-ring on the filter cover for damage; replace if needed. Install the new oil filter, making sure it's oriented the same as the old one (open side out). Reinstall the cover and torque the bolts as specified in your owner‘s manual.
  
• Replace the Drain Bolt and Washer
  Clean the drain plug and install a new crush washer. Reinstall the drain plug by hand, then tighten with a torque wrench to the manufacturer's specification (be careful not to overtighten!). Clean any spilled oil from the area.
  KLX140R L Note—Damaged drain plug threads are common if overtightened – always torque properly.
  
• Add Fresh Oil
  Use a clean funnel to pour fresh 10W-40 4-stroke motorcycle oil into the fill hole where you removed the dipstick. Add just under the full capacity (about 1.0 to 1.1 liters for most KLX140 models; check your manual). Wait a moment and check the level with the dipstick (wipe, insert without threading, then remove and read).
  Do not overfill; overfilling can cause oil aeration and leaks.
  
• Check for Leaks and Repeat Oil Level Check
  Start the engine and let it idle for 30–60 seconds. Shut off the engine, wait another minute, then check around the drain bolt and filter cover for leaks. Top up oil as needed – always measure on level ground, bike upright.
  
• Proper Disposal
  Take your used oil and filter to a recycling facility or auto parts store that accepts used oil. Never dump oil down the drain or in the trash.

KLX140R L (2010–2021) Model Specific Call-Outs

• All KLX140 series from 2010–2021 share the same oil change procedure and specs, including the R, L, RL, and G (big wheel) models. The 2021 KLX140R L uses the same filter, drain plug, and crush washer as earlier years.
  
• No tool-less filter access — you must remove three bolts to access the oil filter cover.
• The dipstick O-ring should be inspected every oil change; replace at first sign of deterioration or leaking.
  
• Always use motorcycle-specific oil (not auto oil) for proper clutch function and protection.
• The engine holds about 1.1 liters (1.2 quarts) of oil with filter change, but always double-check the sight glass or dipstick after filling.

Tips for a Cleaner Oil Change

• Lay down cardboard or old newspaper to catch any spills.
• Have plenty of rags or shop towels ready, especially when removing the oil filter cover.
• Clean the filling area before opening to prevent debris from entering the engine.

Final Thoughts

• Changing the oil yourself saves money and keeps you familiar with your KLX140R L‘s condition.
• Maintain oil change intervals per your owner‘s manual, especially after hard riding or dusty conditions.

For more expert tips, OEM parts, and supplies, always trust MotoSport.com for your dirt bike maintenance needs.

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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.