How to change the oil in a 2020 Yamaha YZ250 Dirt Bike

How to Change the Oil in a 2020 Yamaha YZ250: A Complete Guide by MotoSport.com

Shop parts for a 2020 Yamaha YZ250 Dirt Bike.

Changing the oil regularly in your 2020 Yamaha YZ250 is a critical part of keeping your bike running at peak performance. The YZ250 is a two-stroke motocross bike, and its gearbox requires oil changes to maintain smooth shifting and prevent wear. While the process is straightforward, following the right steps and using the proper tools is essential for longevity and reliability. Here is your proprietary MotoSport.com guide for this specific make and model.

Tools and Supplies Needed

• 10mm or 12mm socket or wrench (check your drain bolt size–most are 12mm, but confirm beforehand)
• Drain pan to collect used oil
• Funnel for refilling oil
• Fresh two-stroke gearbox/transmission oil (check your manual, but .85 US quarts is the typical capacity for YZ250 gearboxes)
• Clean rag for wiping up drips and cleaning parts
• Torque wrench (recommended to ensure proper bolt tightness)
• New crush washer or gasket for the drain bolt (recommended for resealing)
• Gloves (optional, but helps keep your hands clean)

Step-by-Step Oil Change Instructions

• Warm up the engine
  Start your YZ250 and let it idle for 3-5 minutes, or take a short easy ride. This helps the oil flow out more smoothly by reducing its viscosity. Do not attempt to drain cold oil; warm oil removes contaminants more effectively.
• Shut off the engine
  Turn off the bike and let it sit for a minute so the oil settles at the bottom of the crankcase.
• Set up your workspace
  Place the bike on a stand for stability. Position the drain pan underneath the engine where the drain bolt is located. On the YZ250, the drain bolt is situated at the bottom of the crankcase, usually on the left side.
• Remove the oil drain bolt
  Use your socket or wrench to loosen (counterclockwise) and remove the drain bolt. Be ready for oil to drain quickly. Inspect the drain bolt for metal particles or residue, and clean it thoroughly. Note: there is no oil filter to replace in 2020 Yamaha YZ250 two-strokes.
• Remove the oil fill cap
  Taking off the fill cap at this stage prevents vacuum lock and allows oil to flow out faster.
• Allow all oil to drain completely
  Let the oil finish dripping into the pan. This could take a few minutes. If you want to be thorough, tip the bike gently from side to side to ensure all old oil is out.
• Replace the drain bolt (and washer, if you have a new one)
  Once the oil has drained, replace the drain bolt with a new crush washer or gasket if possible to prevent leaks. Torque the drain bolt to manufacturer specifications (usually around 13 ft-lbs, but consult your manual).
• Refill with new oil
  Using a funnel, pour in the recommended type and amount of gearbox/transmission oil (.85 US quarts is typical for this model) into the fill hole. Make sure to use the correct type–do not use engine oil for two-stroke crankcases; instead, use oil formulated for two-stroke transmissions.
• Replace the fill cap
  Secure the fill cap tightly by hand.
• Check for leaks
  Wipe down any spilled oil. Start the bike and let it idle briefly, then inspect the drain bolt and crankcase area for leaks.
• Dispose of the used oil responsibly
  Pour the old oil into a sealed container and bring it to a local recycling center or auto parts store that accepts used oil.

2020 Yamaha YZ250 Model-Specific Tips

• No oil filter: The 2020 Yamaha YZ250 is a two-stroke, which means the crankcase has oil dedicated only to the transmission (gearbox), not to the engine itself. There is no engine oil filter to change; you simply drain and replace the gearbox oil.
• Drain bolt location: The drain bolt is usually bottom-left on the crankcase; reference your manual if unsure.
• Oil volume: Yamaha recommends approximately .85 US quarts of transmission oil for each change. Always confirm fluid levels after a change and adjust as needed.
• Inspection: When removing the drain bolt, check for metal shavings or debris on the bolt–s magnet. A small amount is normal, but heavy buildup can indicate transmission wear.
• Recommended oils: Use a high-quality two-stroke gearbox/transmission oil with suitable additives for clutch and gear protection. Do not substitute with four-stroke engine oil.

Final Checklist

• Double-check oil level after running the engine briefly.
• Inspect for leaks at the drain bolt and fill plug.
• Ensure you have used the correct oil type and volume for the 2020 YZ250.
• Ride conservatively after an oil change to ensure everything is properly seated and sealed.
• Document the oil change in your maintenance log for reference.

Following this guide ensures your 2020 Yamaha YZ250 transmission runs smoothly and reliably, keeping you in front of the pack. For all your parts, fluids, and riding gear, trust MotoSport.com, and check your Yamaha Owner's Manual for the most up-to-date specifications.

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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.